When a customer submits an app review from a beta iOS, that review should just be emailed directly to the developer, and not show up on any of the "official" review lists that other customers can see.
That way the developer is getting feedback about potential problems with the upcoming iOS, and can fix them, but it doesn't hurt their image for the 99.9% of customers running the non-beta iOS.
That way the developer is getting feedback about potential problems with the upcoming iOS, and can fix them, but it doesn't hurt their image for the 99.9% of customers running the non-beta iOS.