All Kemco games just appear. No upcoming thread, no hype, they simply pop up every 6 months or sth like that.
Yeah, there may not be a definitive release schedule (or at least none that they share) for Kemco ports. But they're one of the post prolific turn-based RPG devs on the store. Alphadia 2 came out a few weeks ago and they seem to do a pretty good job in translation / localization of their releases. So I'be been pretty happy with the quality and frequency of their releases.
If anything my problem with Kemco releases are that they occur too frequently for me to be able to play them before the next release. I've got a Kemco backlog, but that makes it easy to wait for them to go on sale. Good quality iOS RPGs. Without trumpets or drum rolls heralding their arrival Kemco just burst on the english language app store and haven't seem to let up since.