Originally Posted by Legion
So how does this event that has already happened in the past (because it is part of our past) impact our world 30+ years later? My guess is that the time traveler is the culprit and their actions change the future.
The event of 1973 gave birth to the events of the original trilogy, the Wolverine films & the present of Days of Future Past. The time traveler's actions as he or she goes back to 1973 will forever change the events of the original trilogy and the Wolverine films.
Days of Future Past at the end of the day is still First Class 2. The next X-Men film will most probably continue the story of the 1973 ensemble.