Looks like there will be some visual indicators but not the hard numbers necessarilly.
Bandwidth, data usage, and stream quality
https://support.google.com/stadia/answer/9607891
Honestly I don't expect it. They don't want people thinking about it. Seeing a screen full of bad stats would likely just make people expect it to be bad, when in fact, it may still play fine or well enough that they wouldn't have noticed otherwise.
At the end of the day all that matters is if the experience is good enough for the player or not, and statistics on the UI won't really change things.