I'm betting the gun scare is the reason everything is out of stock on it. Those who bought it when it first came out went and bought up all the ammo when the scare started.
However, I also don't anticipate the round being around for too long. First, because it's proprietary at this point. And secondly, as you said yourself, bias toward RIA.
It's probably a good thing that they include the 9mm barrel. That way in a couple years people will only have the .22TCM barrel as a paperweight and not the whole gun.