unfortunately, there is no public roadmap related to rollout Stadia to new devices and operating systems. You might want to follow the Stadia team on Twitter to stay up to date. (https://twitter.com/googlestadia)
Neverthless, Apple does forbid such game streaming apps like Stadia or xCloud on iOS. That means it is not allowed to bring Stadia to iOS.
Which controller do you mean? A lot of them work already wirelessly. Please see: https://support.google.com/stadia/answer/9578631
it’s a shame Apple don’t allow too many people into there system as I mainly have apple products
on the controller front it’s state that the goodie stadia controller has to be connect to a laptop and tablet and android phones wired eg with a cable?