I don't think that Bryan Singer would invalidate his own two movies in an attempt to reboot the franchise. "X3" sure because he didn't direct that film and probably the reason why he chose to ignore elements in that thread. There's no reason that First Class has to be a complete reboot, hypothetically or not. I don't get why you would need to change anything to make it fit "2011".
to be changed (as I said in my post). It's just for fun.