Originally Posted by psylockolussus
I don't think we can also view DOFP as a prequel. The first three movies had scenes set in the past too. DOFP will be similar to that when we see scenes set in the past. Then time-traveling to the past and changing the past also rules out the definition of a prequel. When the future X-Men go to the past, they are rewriting the history. So the film won't just shows things that happened in the past. So it can be considered as a prequel film.
But you're under the assumption the 70s arnt going to be a major focus. Its not a flashback.
This film could mostly take place in the 70s (like X-men origins) which was also the 70s and considered a prequel .
This film is just as much a prequel to the OT as it is a sequel to it.