It seems like they are trying to unify the UX for vision OS and other devices and have them finally morph with the AR interfaces that are to come. There is probably a bigger vision behind this than just shiny visuals.
Maybe they just made a bad UI/UX change.
With how badly Apple's VR headset actually sold, I don't think they're going to for a unified AR-first approach just yet. Then again, Apple did think their VR headset was a good idea, so maybe they're just high on their own supply.