I can’t tell if you’re serious or not, but I know some people believe this is a tell tale.
For those people, exactly why would developers update apps for an OS for which they can’t publicly release features based on its new APIs?
The answer: they wouldn’t.
App updates at this stage of OS development and testing rarely have anything to do with the timing of a new OS beta (I say rarely, because I know some banking apps did release updates to permit beta testers of iOS 14 to keep using their apps without being deemed jailbreakers).