They're pretty up front about the fact that the final result is going to have be some sort of compromise.

Based on the words of the most involved proponents of the movement have said, the absolute least they could be forced into accepting would be "Developers can't sue people hosting reverse engineered servers after the main game has gone offline". Which is trivial to comply with (just don't sue someone), but probably insufficient for living up to the main messaging of the movement (since there's a lot more games that people care about preserving than games people care enough about preserving to completely re-implement servers for).

Slightly more reasonably, there's the pitch of "release your server binaries". As the market stands at the moment, that'd be difficult, because in large studios it's common to have all sorts of licensed software involved in hosting your backend, but it's the kind of thing that's pretty trivially responded to on new projects: companies selling software for game service backends would have to adjust their licenses in response to their customers' legal requirements, but that's far from impossible given all the licensed code that's running on client machines already.

In the best possible world, consumers would get access to the source code of the entire project after the company is done making money on it, but everyone involved seems to think that's a pipe dream.