I can't feel any excitement for planning after Apocalypse.
Here's what I would have done
instead though:
Deadpool (early 2016) Dir: Tim Miller.
OT X-Men Sequel (summer 2016) Dir: Bryan Singer. Swan song for the original cast. Apocalypse as the villain, unleashed as a direct result of the heroes messing with time travel. that's what everyone wanted after all those cameos in DOFP.
Mystique (early 2017) Dir: ??? Set soon after the events of DOFP, a kind of spy thriller where Raven continues to help mutants and uncover evil human plots. Small role for Hugh Jackman to tie up loose ends.
Wolverine 3 (late 2017) Dir: James Mangold. As planned.
New Mutants (early 2018) Dir: Josh Boon. Present day setting. Couple of OT cameos. Sounded promising at first, but so did FF and X:A. Should we give it the BOD?
Deadpool 2 (summer 2018) Dir: Tim Miller. The character's success earns him a summer release. Feturing Cable, of course.
Magneto (late 2018) Dir: ??? Fassbender gets to stretch his acting muscles in the long discussed Magneto spin-off, set a few years after DOFP. Basically all of Erik's dramatic material from XM:A, with much more time and depth. Features Evan Peters as Quicksilver and maybe another sibling or two. All about family. Cameo for McAvoy.
I'd watch that.
PT X-Men Sequel (summer 2019) Dir: Matthew Vaughn. A proper, 80's-set finale for the First cast trilogy. Lawrence and Fassbender have fulfilled their contractual obligations already but can return in smaller roles.
Gambit (late 2019) Dir: Doug Liman. Channing Tatum's introduction to the X-Men world. A supporting role for Anna Paquin as Rogue, filling a similar position as Collossus did in Deadpool.
X-Force (summer 2020) Dir: Tim Miller.
I'd be hyped, but I feel like Suicide Squad beat them to it. Also feel Marvel's going to beat them to the first superheroine solo film. Oh, Fox. It has the best franchise for first everything (LGBT, women, race/ethnicities), and such a great message, it could be academy award-worthy stuff.