Hmm. What could staff do here? Or is it possible for a co-author to hijack a game? The short help only tells that new admins could also edit admins, but I hope they can not remove the original admin. This would be a blatant security oversight.
Assuming this is not possible, there is one uploader that has the project on the account. If that master account removes the co-authors, how should Itch know if that was the correct representation of the game's legal status? Would they even be able to enforce any joint copyright? I doubt this. While they call it co-author, it just is admin privileges for a project. Being listed as co-author without admin rights is an often requested feature.
If being removed as adming from the project is all that was done, I do not see anything staff could do.
If the game was modiefied in a way that there are copyright issues, than there could be grounds to remove the project.
Or am I misunderstanding something here or missing something?