There are two parts to this: 1) the software; 2) the features.
The Software
If you have a Plex Pass you can download Plex Pass releases from plex.tv, the update button in Plex Media Server settings, etc.
The Plex Pass versions are beta builds. They have features, bug fixes, etc that are not considered release quality. Sometimes previously working features break or do not work as intended while all the kinks get worked out.
Eventually, one of the Plex Pass builds is deemed stable enough to release to the wider audience. It then goes from beta to released status.
You can see this in the release notes. There will be several beta releases, then one is declared available to everyone, and the beta builds start again.
The Features
A Plex Pass enables certain features not available to the non-Plex Pass users. See Plex: Free vs Paid.
When you claim your server, it checks in with plex.tv, sees what license you have, and enables the correct set of features.
If a non-Plex Pass user installs a beta release on their server it will still load, run, etc. They just won’t have access to any Plex Pass features.
