A few reasons, some with more grain of salt than others.
- GG, ND, SSM and MM were highlighted in old Shu interviews as teams that were expanding to be two-project teams. We know SSM failed at it, reverting back to 1-team, but for all intents and purpose, it doesn't seem like there was any changes in the other studios to hint that ex-devs on project #2 are now working on project #1.
- Steven der Heide is still listed as "Game Director' at GG, and he's not part of the Horizon team. That implies there is a team within GG that's presumably working on something not!Horizon.
- Rex Crowle, obviously just finished Tearaway : Unfolded, so we don't know if he's going to fold into the dreams team. It's just a guess on my part that he'll be working on a new project instead of dreams.