It's a bit trite but I think an underlying point here is that stakes and outlook depend on the era.
In year 10, the issue is preventing the completion of Mother Mold, not just because it's another super sentinel, but because it could bring about the emergence of Nimrod, the omega point of AI development that invariably marks the moment Sentinels gain the upper hand over mutants.
In year 100, Apocalypse and the last X-Men of Asteroid K are fighting for the survival of mutants against Nimrod. We don't really know how that turns out BTW, but there's nothing about Nimbus then.
In year 1,000, mutants and AIs have apparently converged into a single Terran civilization, and their stake is the survival of their civilization at a galactic or intergalactic scale. They put the Nimbus plan in motion 700 years before that because they apparently understood that in the long run, as their civilization grew, it would be judged by the (a?) Phalanx. If they were found lacking, Earth civilization would ultimately be processed as organic waste by a Technarch, while if they were deemed developed enough, they would evolve to the next stage, that is ascension. That's why they had to create a Worldmind through the Nimbus plan.
At least, that's my understanding of the material at the end.
Basically. I think that in the long run, it's hard to really distinguish mutants from AIs, in that both are natural evolutions of mankind and are apparently meshed together in what appears to be a single society. From that point of view, Ascension seems desirable.
That's a point Hickman has been hammering every week: we've always seen AIs as tools created by Homo sapiens, that sometimes turn on their creator, but AI will eventually emerge, regardless of particular events, because it's part of an evolutionary, historical process, and as such, it's an inevitability like mutants were.
