Originally Posted by The Original Bamfer
Okay, this film is all about changing decades of events. Bringing back either Scott, Jean or both should arise no questions. It's all explained by the fact the course of history has been changed... there's really no misunderstanding that when the film itself revolves around the concept of rewriting history. Yes, it happens because Sentinels have taken over mutants, but there are naturally other advantages... like bringing back Xavier's most beloved students.
I'm also fairly certain this will be the last time we see the "young" characters. If they continue on with the series, I'm guessing it'll be a present-day affair.
The OT would be future and chances are not present day if it is 2023 like many are speculating
At comic con during an interview with mcavoy (in same room as Stewart,mckellen,fassbender and singer) he seems to believe there will be another FC film and as he has read the script so there must be a door open for the younger versions of the characters, I think the 3rd will be the last for FC though