I've found that you simply can't just pick up an X-comic without being lost. I collected in the 90s and early 00s and then stopped. I've been periodically coming back every now and again that last 5 years or so but I'm not sure I can. At least not randomly. If it's to make any sense, I've gotta go back to when I stopped and read chronologically. Here are my notes, mostly so I can remember what happened, on this volume.

Prof X, who regained the ability to walk sometime, give up on integration and partners with Krakoa, Magneto, and Moira McTaggart to create a mutant nation on the living island. Sounds like the mutant edition of Garvyism (as in Marcus).

I think the collection interfiles the two stories to jump around the timeline. There are four periods in time:
The "current" one where the mutant nation is being created.
The 10 years in the future one where it exists.
The 100 years in the future one where Nimrod the Lesser rules, as the Machine Uprising has happened.
The 1000 years in the future one where The Post-Human Race is working with The Phallanx to subsume human knowledge.

It was interesting seeing the likes of Mr. Sinister and Apocalypse sitting beside the X-Men.

I think Moira's reincarnation power, where she remembers her previous lives and since time is cyclical, she can try again with the knowledge of her past failures. That didn't sit well with me as a Western Buddhist.

I wish they'd stuck to one storyline They try to tell too many at once to keep the reader guessing but it actually took me away from the story. I would have preferred they tell one really good story in the stead of 4 potentially good stories. For me the creation of the mutant nation was the best.