If a 3rd batch does happen, any remaining arc that’s 3 or more episodes from seasons 1-6 would be included in it, that includes at least 8 remaining so far. The only exception perhaps being the Domino Squad/Rookies arc since it’s spread out over a much longer period of time, so I’m not sure if cutting it into a film edit really works all that well.
For now, I hope people enjoy what we’ve got.