Originally Posted by Nell2ThaIzzay
If they are planning on continuing with main trilogy sequels, then I wouldn't expect any sort of major "retconning" or X-Men 3 / Origins removal. No way are they going to break / erase continuity if they are planning on sequels to that continuity.
If a new timeline is established by the time travel, they don't have to erase anything. It still exists in its own timeline. That's what they did in Star Trek.
It depends if they follow the Star Trek model or opt for something different, such as the changes made in the past having a ripple effect through the existing films and making SOME changes to events/outcomes.