The latest beta is nothing more or less than the previous beta (2.0.4.5) with an added warning message for anyone using the Amazon Cloud Drive. This service will be discontinued next month, so users (especially in the beta channel) should be informed soon about this shutdown.
After the latest beta, a lot of new features and improvements have been added. These changes require modifications to the database structure, but have not been tested enough to be merged to the beta version.
This is why the database of the latest beta have a lower version number than the latest experimental and canary versions. “Updating” from a recent canary or experimental version will effectively be a downgrade to respectively version 2.0.4.4 and 2.0.4.2.
As stated by @kenkendk there’s no need to update to this version, unless you’re in the beta channel and want to be informed by the upcoming closure of the ACD service: