I do not get the point of these claims.

All of these are assumptions and accusations that as said are backed by nothing. Yes it is possible and the number of new institutional investors might just make this case more realistic but unless stated or there is a hard proof of them selling to dump, there is no point to make these claims. Because they will not be proven true anyway. But oh well, we will always hear these kinds of assumptions. There is always someone saying something about manipulation.