I don't think the X-Men just sat around for 50+ years though in the time between the attempt on Nixon's life and when Wolverine "woke up" again. Just looking at Rogue's white hair and Jean's bright red hair should indicate that X1 and X2 did occur to some degree, or at least similar events that causes things like that.
I didn't say they sat around. I think the events of DOFP combined with Apocalypse's appearance in the 80s would do far too much to warp the timeline for things to occur in the same way. Kinda, sorta, vaguely similar? Maybe. Jean is Phoenix. There's a million different ways for her cosmic powers to trigger.