Except that studio is still open and has a game that is bringing in muchos dinero.
Also one of the biggest, at least most vocal complaints about GW2 is it's not GW1. And since that game, GW1, is no longer reported and that there isn't a way to even estimate the number of people still playing it. That game's cash shop was fairly limited and nothing new on it for quite a while. I imagine if the last numbers we had is any indication, it's probably has sales of less than $1 million a quarter now.
Don't forget, ArenaNet seems to have a more independent relationship with NCSOFT. The seem to have no problem releasing product on their schedule and have publicly "corrected" NCSOFT's Investor's Conference Call at least twice since I've been looking at them. I think ArenaNet got some really nice terms when they were sold including a big fat escape button. And right now the only "growth" the NCSOFT has YoY is GW2. They got to keep them happy.