If Aigis was gonna close, it'd have done so half a year ago.

Since Dev Tea finally stepped up and started implementing things that were long overdue, it probably won't be going away anytime soon.

As for other games, FKG and Kamihime have steady playerbases and income as well, while PPS/OI/IW/DP are still sustained by whales. SenPro is probably next on the chopping block.