Originally Posted by Double B
Well, realistically, you can see X1-DOFP as one huge arc, then DOFP acting as a new beginning.
There will be changes, people being alive who died in the original timeline, but that doesn't mean that the events we saw can't still have happened, more or less, with a few tiny changes.
In a roundabout way, by doing it like this, the events of X1 onwards are still important/canon because, without them, we wouldn't get this 'better world' with a few changes.
You know, I could honestly see the franchise taking this route.
Personally I never saw a need for First Class (and any other "prequel" type X films) to match up exactly with the originals. I would have been content with a "loose" reboot.
That being said, I never saw a need for Abrams Star Trek to offer an in-universe explanation for its changes to TOS either, but Abrams went that route. Could be that Singer et al are taking a page from his playbook.