Why weren't FutureWolverines interactions with PastXavier and PastMagneto, clearly affecting the memories of PresentXavier and PresentMagneto silmutaneously (in the future setting) whilst they're in the temple room with kitty? Wouldn't it have been an instantaneous reaction - I mean all the mutants disappeared from the temple after PastMystique stopped herself from shooting trask. Technically, the PresentXavier and PresentMagneto in the room would not be the same persons before and after the moment Futurewolverine met them for the first time as it was a completely new event from the original timeline....right?

OR is it because the shooting of Trask was the event that would causes the true fork in the timeline causing the diverge, so anything leading up to that is negligible in the grand scheme of things and wouldn't have changed PresentXaviers and PresentMagnetos memories ?