The protocol is ActivityPub, which was standardized by the W3C. Lemmy (nor KBin, Mastodon, PeerTube, etc.) have control over that standard. They can suggest things, but if Lemmy were to break compatibility with ActivityPub, you bet your ass people will fork the project, or just switch to KBin.

See: OpenOffice being aquired by Oracle and then being forked to LibreOffice for an example

But yeah, we can never let our collective guard down.