You aren’t wrong for how beta releases can be used by a company, but the reliability of betas released in the past vs being released recently has changed. Plex reps used to suggest using the betas for the latest features soonest without much cause for issues because of how reliable they were because they were essentially Release Candidates. Now it’s “you should expect bugs, it’s a beta”.
Bug reports on server issues with betas usually do get picked up quick.
That’s fine if that change from RC to Beta has happened, but in that case, it would be useful to include more detail in the beta release posts for the beta testers as part of that shift. Folks will still be happy to test but this way they could be more aware of what to keep an eye out on. That’s all. 
Edit: It’s not slamming Plex directly really… any company that puts out betas for testers should include all significant details and “There was a very large refactor under the hood with metadata loading/refreshing” seems significant. Other places I test betas for do that for us. Heck, the new web version doesn’t even have a release note for any changes since 4.146.0 and this one updates us to 4.147.1 and usually the Plex Server web client is behind a few versions from Plex Web.
