All games on Stadia whether Stadia Pro or the free version are 60fps according to Google (4K/60 for Stadia Pro, 1080/60 for Stadia free, scales down to 720p/60 if you connection doesn't have the bandwidth for 1080/60). I would assume you essentially need the games running at least 60fps to make streaming truly viable.
Even Red Dead at 60fps? Hmmm
SamSho Switch releases December 12th in Japan. That's all that's been announced afaik