The only new characters what the white haired girl with the guitar/cello/axe on her back. I believe her fighting style is similar to A.B.A. from Guilty Gear (Isuka and onward) shown in a still at the end of the video and Roa (the guy shown after that).

Aozaki Aoko, more easily known as Shiki's "teacher," was in ReAct (and possibly earlier), and White Len and Neko Arc Chaos were both in ReAct ver. B in the arcades.