It's probably not temporary. I don't see how they can fix the original crap accessibility liquid glass version without toning down the transparency / glass effect in some form.it wouldn’t surprise me to learn that Apple toned down the liquid glass as a quick temporary fix, and plan to revert back to a more glassy effect once they refine it further. There are a few reasons they would do this. From a testing standpoint, I feel like they have received a metric ton of feedback about the contrast issues, and may be doing this frosted effect so we can move past it for now. Pure conjecture on my part, but I really hope the frosted effect is temporary. I actually like quite a bit of the glass design and hope to get some of it back.
It’s almost like they forced on reduce transparency.
The best of both worlds is probably going to be a hybrid, where it's the "can't read crap / not accessible at all" liquid glass from B1 and promo material in motion (e.g. when you scroll or when you tap it to change tabs or it morphs it's form, it goes full liquid glass or turns part of the area you tap into liquid) but starts to freeze up and become more frosted glass once it's settled down (e.g. when you stop scrolling or are no longer tapping it). The hard part is probably balancing the 2 states, considering the UI has a lot of subtle animations and movements (e.g. you need to ensure that notification content is readable on the lock screen when sifting through your backlog, without having to stop scrolling 24/7). There should probably be a threshold, e.g. not turning it into liquid glass with minimal movement but actual scroll.