I think we’re on the same page! I think most people are pretty happy with their experience and I really doubt that Universal is being deceptive, intentional or otherwise. But I don’t think preview is a universal inference for technical rehearsal, at least, not for the layperson. I mean, “preview” in this context is really only commonly used in Broadway theater, right? And generally those previews are pretty well-polished and are more creative changes than anything.
This is really only in response to the “technical rehearsal means no complaints allowed” crowd that is frustrating me. The replies on the Blog Mickey virtual line tweet, for example, are really nasty right now.