I agree it's a welcome change. The user experience is much better this way.
Since I updated my device to visionOS 2 beta, I've installed my app via TestFlight multiple times, and I don't think I've seen the notice you described except once, immediately after I first installed visionOS 2 beta. So, it appears this is not something I can easily test without reinstalling visionOS 2.
Also, since I no longer have visionOS 1 installed, there's now no easy way to test the original visionOS 1 immersive space permission alert either. The visionOS 1 simulator has never supported presentation of the immersive space permission alert, so that's not an option.
This is all unfortunate, but thank you for responding. It's helpful to know I'm not overlooking something obvious.