This seems to have been announced a couple of weeks ago, so we don't need to just trust the tweet: https://www.macworld.com/article/1377200/apple-to-limit-aird... Having it open to everyone for only a limited amount of time actually kind of seems like the right thing, but it's hard to come up with a legit explanation for why they rushed that change to China first.
The timing of the change seems quite conspicuous [1], and it's also weird that Apple would introduce this in China first and only roll it out to the rest of the world next year. The same article mentions that Apple blocks the Taiwanese flag emoji in China, for which it's hard to come up with an explanation other than bowing to censorship. 1: https://chinadigitaltimes.net/2022/11/netizen-voices-apple-r...
If one believes Elon Musk's view of the Twitter situation with the app store, Apple seems to be for more censorship!