How about an independent third party (outside the company) that has a binding contract with Facebook? This third party could handle other social media sites as well that choose to opt in.

Personally, I'd rather just see Facebook stop being such a huge force in the market and instead move toward a decentralized model like Mastodon with ActivityPub, but there's no way Facebook is going to go that voluntarily, nor is there any reason that they should.

So, at the very least, they could make this organization completely outside of Facebook's oversight, kind of like how the ESRB works. Maybe this is their end goal, idk, but if they choose to retain control, people are always going to be skeptical.