Originally Posted by psyonic
What if the DoFP timeline in the movie is an alternate world where X3 didn't take place, and what actually happened is what exactly in the comics i.e Senator Kelly assassinated, passing of Registration Act, mutant internment camps, Sentinels. This is a viable way of forgetting X3 and skipping all the deaths and the cure.
But if Senator Kelly's assassination happens after X2 why the need to go back to the 60s?
I think it's possible that the apocalyptic future happens in a timeline where none of the X1-X3 happened at all and where the characters have had completely different lives. So the crucial event in the 60s is where the different timelines diverge:
1) Timeline where the 60s event happens and which leads to apocalyptic future, in which X1-X3 never happened.
2) Timeline in which the event is averted and in which X1-X3 happens.