My idea is that the final DOX arc against Orchis sees them watching the dreams of mankind trumping mutants via the path of Homo Novissimization fizzle out, and thus they fall into a cosmic suicidal temper tantrum: they will destroy mutantkind even if it means sacrificing humanity and the very fabric of reality to do so.
They might go the unexpected path of using transcendental magic to turn "existence" itself into a toxic environment for mutants (a la T-cloud now covering not just the atmosphere but the fabric of existence itself), tying them into parallel Earths as well. Krakoa decides that for mutant survival, destroying all parallel universes contributing into the "toxic existence environment" for mutants is no skin off their collective noises (especially as the Five and X - he survived, natch - will soon be overtaxed reviving mutants dying from Orchis' suicide gambit). The Excalibur team uses their near-fully-developed "mutant magic" library to cast a spell that destroys all parallel universes feeding into the anti-mutant existence of Earth-616.
As a result, all Marvel media winks out. The last Phase 4 MCU film sees the setting cosmically destroyed by the Krakoan magic. All ongoing Marvel TV shows and animations at the time will end likewise, while all complete Marvel productions, especially showing on Disney+, will abruptly disappear from the streaming library; accessing them only leads to a screen with the current X-logo. Oh and by the way, these include all X-Men programs as well (films, TAS, Evolution, WatX). They're part of the contributing factors in Orchis' anti-mutant existence field. And to the cynical Krakoans, "If we can't get a happy ending for ourselves, then they don't deserve theirs." The power of Marvel SYNERGY under Feige!
With the parallel-Earths threat dealt with, Krakoa will then have to eliminate the 616-local power sources for the toxic existence: all inhabited planets in their native universe outside of Earth, and not just all humans but all living organisms - especially sapient ones - that carry no X-gene. Phoenix power wipes out everything off-Earth, and the rest of the Krakoans go on the final human xenocide with the Avengers and all non-X Marvels getting massacred (in graphic Walking Dead/WH40K snuff art quality). Orchis, especially Doc Gregor, hope that they could stave off their inevitable extinction until the toxic existence spell reaches critical mass that it will continue on even if they are gone, and the Krakoans know at least that if they kill all non-mutants before that threshold is reached, their problems are over at last. In the end, there are no more non-mutants, Marvel Comics is rebranded into just X-Men Comics, and mutants begin spreading out into the world.
Did they stop the toxic existence spell before it reached critical mass? Or will mutants continue dropping dead for no reason even after all existential threats have been destroyed? That could be the first post-DOX arc. And I'm wondering if the Marvel-human-xenocide-advocate fans of X would have to buy plastic covers for the DOX climax issues to protect from "fluids" while reading.
Maybe it's just my experience from most of my past forums before signing onto CBR, as a lot of my other stomping grounds do take their post content super seriously, as you say.