Have more faith, Yoshida is involved. It looks more serious, and more like an Ivalice type setting, and given it probably won't be out for a few years this has to be some early gameplay we saw. We'll likely see other characters later, but your points on the multiple party member thing is legit - they've been shying away from that in various forms for a bit, but they really seem to have gotten a good method of controlling multiple characters at once in FF7R - though they left the AI of the non-controlled characters dumbed down I think, for reasons.