Couldn't Synadia just fork what they want to and rebrand for a commercial new product, and go forward from there?
If they wanted to backport or keep contributing to the open source project they could, or leave some parts open source going forward, while forking only the server for example, to do that.
Kind of like how RHEL used to still provide contributions to CentOS for a long time (although I think that ended at some point too).