I agree, nothing really new about the lame Control panel.
I installed tvOS 15 yesterday afternoon as soon as it was released and used it for several hours until I went to bed last night. I really don't see much that has changed. That is probably a good thing considering how gosh awful iPadOS 15 is now with the screwed up Home pages that waste space and look terrible and the screwed up new interface on Safari that causes you to have to make multiple gestures/presses to open the sidebar and navigate to where you were and multiple gestures/presses to close the sidebar. From now on, I wish Apple would concentrate only on squashing bugs and stop changing the interfaces to the point of making them nearly unnavigable. iPadOS 15 is a big mess, and I wish I hadn't installed it. But thankfully tvOS 15 and iOS 15 seem okay. None of them have much new to offer though.
I did have a few minutes of weirdness with the new 2021 remote after updating my ATV 4K 2017 to tvOS 15. The remote refused to work at all for a few minutes, so I restarted the ATV 4K and slowly but surely the remote's functionality returned. I did notice that it had been set to use the trackpad as well as click, which is not how it was set prior to the update. My guess is that once the tvOS upgrade finishes, a separate (apparently hidden) update for the remote takes place. So perhaps the ATV 4K updated then I had to wait a few minutes for the remote to update as well. My Fire TV Cube does something similar when it updates. Apple should make it clear that the remote is updating though so we know what is going on.