If the authors disagree with the journals team, or just get tired of waiting, they can still publish at any time just like with community review. For authors who choose both, the journal's team and community reviewers can interact with each other just as in normal community review.
I think it's a way to provide a stepping stone for people from the existing system towards full community review and would provide logistics to those organizing open journals with teams of high quality reviewers.
The plan is to implement it during the closed beta period. I would welcome feedback on this concept as well :)