Re: X-Men: Part 6 should be set...
Well, assuming they only have Fassbender and McAvoy Co for only one more film under contract, then they can have FC3 set up the final part of the new prequel then "Star Wars" it to a Star Wars 7 kinda.
New/Older Xavier and Magneto working under a new timeline, which completes the reboot, cause of the DOFP changes.
"Great men are forged in fire. It is the privilege of lesser men to light the flame."- War