Good question. Unfortunately, the TLDR is that we won't be attempting to put the game on those platforms.
The general wisdom among game devs is that getting a game onto those platforms is only important if the game requires a high-end gaming rig, and Tonight We Riot does not, so we hadn't given it much thought.
Looking at it right now, the application process for Stadia doesn't look too bad, but if you are going to do it right on either platform you should optimize for touch/phone controls. My internet connection (I'm the programmer who would be working on porting the game onto these platforms) is so weak I don't think I'm equipped to test out those game streaming services, and I also have a couple new projects that would keep me from looking at it for at least a month.
So, sorry it won't be available without a computer/Switch for the foreseeable future.