The only problem with this theory is that Koihime character gacha boost ends in a couple of days. If there's no new characters to replace the boost with, why end it?
they could wait til the end of koihime to post envy, if they did they'll likely add uriel and snow raphael after the koihime gacha ends cause we'd get them in garuda/typhon rematch which we had much earlier than scheduled in dmm...
selling brand new account with L/E SSR and full plus more fire team.