One caveat with this: if your project is open source and has accepted submissions from non-affiliated entities, you would either need to get them to assign the rights to that code to RethinkDB or remove them from the source if you were to relicense under something that would break the AGPL. This is where things like code releases come in.

This is also why many open source startups don't accept code submissions from outsiders until they've determined they're going down the path of a consulting-focused business model. It's just too risky.