I doubt anybody in a position to know will post on this board. But rumors are likely to be plentiful in either direction.
Monthly Prius production has been increasing this year. Keep an eye on it and look for trends. If it goes lower, your explanation would be a possibility. If it doesn't go down, then we'd know the new Hybrids aren't eating into Prius parts inventories.
And just "IF" there is any truth to the fact that the Prius is being subsidised by Toyota to get hybrids successfully on the roads and now with the price of gas the public has been enlightened to the advantage of owning a hybrid, it is time to start making a profit out of this six thousand dollar "synergy" power plant. Ergo, the Camry at twenty nine thousand.
I still believe "we all bought smart."