With the way the films are done now, there's not really any main X-Factor line up to pull every character perfectly, so they'll have to be made up from a few different ones or have different characters added altogether. The main team is like that, they're doing that with X-Force, so there's no reason to not expect that with this team should they ever get around to doing it.
Originally Posted by psylockolussus
Spin-offs are risky, FOX should at stick with the OT cast, at best they could do more 3 films with them. Box office success is guaranteed with them. For me, I prefer to watch a string of films with familiar faces.