This is literally what MS did.
The protocol is entirely public :
https://microsoft.github.io/language-server-protocol/ Of course the governance is terrible and MS might choose to change the protocol in a non-forward compatible once "all the fish are in the net" and they want to force everyone to use VSCode because it becomes the only client that's fully compliant.
Even if that were to happen, nothing prevents people to say "I don't want to follow MS protocol anymore, the program I distribute as LSP server follows the last protocol version I agree with, i.e. 3.15" and linking to that protocol. the LSP clients that want to use that lsp server to enhance editing capabilities (or allow smart manipulations of org-files from editors that are not Emacs*) for org-mode files will have to follow the 3.15 protocol if they want the features.
* which seems to be the goal of this endeavour.
I don't feel like answering much more about this subject, I'm more interested in the technical stack to make that thing work than the usual GNU politics to be honest.
Gerry Agbobada