I'm seeing the Mary Sue Factories involved in this, definitely, but considering all of the other buildup involving Selene's escape from the Psychs, and the occasional mentions of an Ispace war involving multiple trans-dimensional organizations, I'm thinking it's not an EPC invasion. It might involve them in some capacity, since that cactus-with-a-sword symbol at the bottom left looks very similar to the symbol for their Department of Arrests, but I'm guessing the real heavy hitters here will be Ispace and their allies.
See, Ispace is sort of like the Department of Elf Protection we used to have, except where ours kept any elves or elf-like creatures save from being afflicted by Sues or maligned by inaccurate descriptions of their character and culture, Ispace is just trying to keep any elves or elf-like creatures(or Eoelc, as I've just now decided to abbreviate it) from being harmed in any way whatsoever. The problem here is that a lot of Mary Sues are Eoelcs, or take on an Eoelc-inian appearance to be more speshul.
Ispace started out as a similar organization to the PPC, at least in theory, protecting not a specific canon but anything in the multiverse that they see as "elven". They believe that if elves are allowed to be damaged and defamed, eventually there will be no more Eoelc of any sort, and that a universe without any elven influence is a universe that is about to fall apart on a cultural level. They're a very specific kind of crazy and dogmatic.
I think that they may have met up with the League of Mary Sue Factories, or at least as many of them as can be gathered under one banner, and negotiated with their leader, nominally the Venomous Tentacula but quite possibly someone who would be less rash and more receptive to their propositions. While the goals and modus operandi of the two organizations are very different, Ispace hates the PPC and the OFUs for oppressing the diversity of Eoelcs by killing Mary Sues and preventing Mary Sues from being born, respectively, and the League hates the entire Canon Protection Initiative for destroying and discrediting their product, and the PPC in particular for warding off their numerous attempts to establish a firm foothold in the multiverse. The Biohazard symbol probably means that they'll be getting supplies from the Flower who took over after PPC Bioengineering was jettisoned during the Reorganization, the mysterious Horsetail. That's the logo of his restructured "BioInc". I've seen him referenced here before, but to my knowledge he has never made an appearance in a story. The Horsetail would have reason to work with Ispace and the League, in part because they'd be one of his company's most interesting and lucrative customers in years, but also because they lost one of their biggest trading partners when the PPC excised them.
Now, the Selene part. Dafydd's been world-hopping recently, and while he's shown up back at the PPC at least once, another time we see him is when he travels to the multiverse of the TCDA. It took a lot of exchange to confirm this, but evidently, Dafydd and Selene's TCDA counterpart broke her out of her cell and took her out of Headquarters, and then exposed her to a device that allowed her to recover at least a portion of her sanity. It's possible that Dafydd was just going to the first multiverse that had the technology to repair the mind of his former partner and old friend, but now that I know the book surrounded by three shapes represents the PPC, that book-with-shapes next to it is starting to look a lot like a gear, isn't it? Dafydd's family and associates have known about Ispace for a while now,, though they hyperbolically refer to it as the "anti-PPC", and Dafydd may be attempting to set up some sort of resistance to it. It is possible that Dafydd, being both an elf and Huinesoron's former self-insert(he's had three or four now; it's crazy), may have been involved with Ispace in the past, but it is more likely that he's heard of it during his travels through the multiverse and knows what the group is capable of.(Of note: Ispace has as of now made confirmed contact with at least one of Huinesoron's other self-inserts. If this starts going meta and ties into the Message, it will officially be one of the most unexpected reacharounds I've seen here, but it probably won't, considering the circumstances, and I'm getting off-topic.) My personal theory is that he's planning on rallying the TCDA and any other vestiges of canon he can find to stand up against it when it finally decides to invade in force. This will, in all likelihood, include several alternate versions of the PPC. The white dog in the Restricted Access box may indicate that we're getting the Mirror DIS in on this, too, since several members of their organization were last seen rebelling against the tyrannical leaders of the Mirror Multiverse and fleeing to some ill-documented corner of the main multiverse, which should be fun. Selene may be an important part of Dafydd's plan, though he could just as likely have broken her out for more sentimental reasons, like a desire to fight off another threat to canon together with his first partner, or a guilt for leaving her in her cell all alone and insane while he's safe in the unpublished haven that he retreated to post-resurrection.
I can't see any sort of symbol that would represent the Neo Abduction Schemers Treaty of Youth, though. Maybe the pink crown with wings. NASTY would almost certainly be involved here in some capacity. They're trans-dimensional fangirls with access to giant robots and the ability to hijack portal devices, which they've used to sneak their members into HQ before, occasionally in large numbers. Judging by their name, they'd also have some sort of stake in wanting to get rid of the PPC, so that they can capture canon characters and locations to have them all for themselves, though several parts of that motive are admittedly largely speculation at this point. They'd make very good soldiers for Ispace's alliance, too: they're motivated enough to have broken into HQ before, they've got giant robots, which are always an advantage, and they most likely do not contain a large number of Eoelcs, so Ispace might see them either as expendable or as people who are capable of operating on their own without Ispace needing to be around to ensure that there aren't any unwarranted elf deaths.
As for what the "Character" and "Access" section mean, I think it might just be how they treat characters and how they bring in employees and/or interact with the outside world. The PPC is restrictive, in that it will only recruit characters from within badfics they encounter or those who fall through plotholes, in small numbers at a time, the TCDA is a little more restrictive in that they limit that to only canons containing steampunk or published before the 1940s or so, and the OFUs hardly ever take on any new staff at all.
To take on the second definition, neither the PPC nor the TCDA want anyone to know that they exist, but the news sometimes gets out anyway, and the OFUs are isolated from pretty much everyone until they bring in a new class or something nasty invades the campus. Meanwhile, BioInc down there would recruit or do business with anyone in the multiverse, since they're a business and would be primarily concerned with profit, and the League would still do business with plenty of people, but they wouldn't advertise broadly, in part because the PPC might step on their salad again and in part because their product is much more specific and refined than the sorts of things BioInc would put out. There are only so many uses for a Sue.
The one major hole in my idea is the fact that the Department of Arrests is all the way down at the bottom, since they'd have more recruits than the PPC, what with the entire Mirror Multiverse being devoted to the production of Mary Sues. Then again, it's possible that this relates to activities within our multiverse, in which case it is entirely justified. People from our multiverse would need to be willing and able to cross time and space to join a Suvian organization for them to pick up recruits or customers from the main multiverse, and those three factors rarely converge.
Respect for Character would not necessarily mean that there was a specific character, and since that's a subtitle to "Respect for Canon", and the bottom of the canon-respect list contains the League of Mary Sue Factories, I'd say that's pretty much locked. Besides, we've dealt with Agents trying to do something pertaining to the murkily defined "power of all of canon" before. It didn't turn out so well, and I mean that from a storytelling standpoint. The people involved mostly came out alive, but it was an unsatisfying story that didn't really take the most of its potential.
So, yeah, it looks to me like it's shaping up to be PPC, alternate-PPCs, and OFUs against forces of uncanon hailing from across the omniverse. Bring it on. If I can see some Agents from the Magical Girl PPC AU fighting off a fangirl-driven giant robot on the deck of a steampunk battleship to rescue it from the dogmatic elves that captured from the protectors of the Victorian era, I will go out very happy.