Seeing as how Crisis on Infinite Earths and all the other in-continuity reboots of DC have been horrendously bad stories, notable only for the fact that they changed continuity, I find the idea of using time travel to create an in-continuity reboot of Star Trek a horrible idea. They want to start Star Trek over from the start and they're covering their asses for the canonites, which means wasting precious screentime on convoluted time travel handwavium.
It's fiction - why does it have to be reconcilable with the original continuity? Aren't we all intelligent enough to simply say - they're rewriting it fromt he beginning? Which, of course, is exactly what they're doing, time travel bs or not.
*Applause* If it's a good movie without the cop out then it doesn't need the cop out.