by TrueLolzor
I would have assumed it was a rules oversight if the card was from a pre-Red Rains deck, but this one comes from a Red Rains expansion, so you'd think they'd have considered its effect in games against a Chimera. So it seems like this was intended, if I'm not missing anything.
Despite us being inside a pve cycle, player cards are designed mainly with pvp in mind. The rules oversight here is ultimates wiping the alterations only from board, there is nothing at this point that can be done specificially for the Rose to remedy that. Rules as written, it sticks around forever. But if you'll ask designer, I believe they'd say that ult should be wiping the Rose as well, they just didn't think of it when wording the ult 4 expansions ago.