From the onset if Elon was to invest in bitcoin openly, if he hadn't done that in secret (I said this because some of the times rich people play trick on us not to realise some investment they have done in secret so the source of some income wouldn't be known by the public or people would not go into the business idea or investment in mass), he would have get involved with bitcoin but he only tried to do that in a smart way just to get the attention his business needed. However, even as being the richest man he could do anything he wants in he wishes and I also agree with you that we can keep arguing on assumptions.