I can certainly see the possibility of single actors buying up btc on the side as a speculative endeavor. However, the idea that said actor will use their media strings to promote it is extremely unlikely to me, as their risk (attack from other influentials, possible social/financial ostracism, assassination if one wants to don that cap) far outweighs the potential benefit (a nebulous amount of one-time profit that may or may not be greater than what they make off of the current system).

Your theory is correct qualitatively, I just disagree on a quantitative basis. I don't think that anyone with enough power to do what you describe would make more from doing so than from continuing on as they are.