The problem is the bankruptcy court/buyer/ex-spouse/whatever may have a different preference. So you may want to set up something legally binding now when everyone is the same agreement.
Could you also solve this by GPL+Commercial license for those that pay?
It also allows people to read, audit, and trust the crypto code, which your model does not. For people like me, that’s a hard pass.
As JWZ once said: "You can't take a dying project, sprinkle it with the magic pixie dust of 'open source,' and have everything magically work out." Has there ever been a case where a company as its last act released their software as open-source, and a community formed and picked it up?
Now, there are interesting communities that form around games, that tend to be a "dead product" after release, and for which there was a source dump (or not, actually): doom, openMW, openRA, etc.
Not saying such examples aren't out there. I just am unaware of any.