From their site: “It is already deployable and useable, and it federates cleanly with many other Fediverse servers (not yet all). However, many things are not yet implemented, and there are plenty of bugs! We foresee entering beta around the beginning of 2024.”. I would say it should be described more as beta by now from that description.
Gmail was in beta for many years whilst it was in production, and Meshtastic only has alpha and beta releases, with no “stable” release. I think some projects feel if they are still adding features it says in beta and never reall is in stable until they stop adding features. But yes they should actually iterate through alpha, beta, RC, stable. Not everyone does, though.