Yeah I'm absolutely the market for this thing. We have an old Google Home that we use as a digital photo frame and Google has progressively destroyed every other piece of functionality we once used on it.
My only complaint is that a truly environmentally friendly company (like Apple claims to be!) would make this OS available for old iPads. I'm quite sure they're capable of running it (or at least a stripped down version thereof) and lots of people have old iPad Minis sitting around.
Cynicism about selling new devices aside, if they really want Siri intelligence on these, old iPads can't do it, and Apple won't (if they can avoid it) sell a "product" with varying features.