I stumbled upon the app today, but I was disappointed to find that it's unavailable. Do we know when it's coming back?

Very soon I hope.

should be pretty soon

I think it's pretty soon, as has been said. I believe that in Japan, they've already released an update that fixed the issue, so hopefully that will be transferred here soon. Not 100% sure on this though, haven't seen any specific sources confirm or deny this.

why was it taken off the eshop in the first place

Smilehax, a primary homebrew entrypoint on any firmware. of course ninty wanted to patch this.

It's back!

@V360 no it isn't. just looked. unfun.

@Dragon it is back but possibly not in your area yet which is why its not showing yet on the Eshop for yours

My area is Europe; is there any case SmileBASIC is regionally exclusive?

possibly but im not sure if its or not but try asking smileboom if you can

I don't think it's out in Europe yet. However, I believe it should come out soon in Europe (they've been working on it, at least). Not sure how "soon" though.