It is as good a theory as any I've heard though still not totally convincing.
If it were a good whale with a budget of benevolence for the platform, it would be even more effective to own up to it. If a big whale came out and said they were pumping SBD to a certain level to reward content creators I think that would boost sentiment immensely and put a price floor in place, would it not?
I am not myself sold on the theory at all. It was mostly an exercise in hypotheticals.