I don't think they're just going to go straight into AOA after DOFP, I don't think it would be smart. There's needs to be some groundwork laid for Apocalypse first before we get any of this otherwise it's all meaningless.
I'd be more than fine with them introducing Mr. Sinister first in the next movie and potentially using Stryfe as the villain in an X-Force movie first that leads up to an AOA style movie.
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