An expert bit of teasing by Bryan Singer, here. He's shot a vine of the on-set canvas seats used by a number of X-Men: Days of Future Past cast, and there's a couple of new names in there.
We were told that Bishop was amongst the lineup, and that he was being played by Omar Sy. We know Sy is in the film, so let's go with that for now.
As for Warpath… well, we might guess Booboo Stewart has that role simply because both character and actor are Native American* though that would assume, for one ting, that there's just one Native American role to be filled, and I don't think we should be too sure about that.
As all of these seats are set out today, expect all of these characters to exist in the "future" timeline. It'll be interesting to see which are still out when Singer gets on to the "past" phase of the production.
*Or, to paraphrase Sandi Toksvig, "as I like to call him, American."