If for some reason the Chinese government decides to put some of its trillions of dollars in T-bonds into Bitcoin... Seem ridiculous
Putting all the foreign currency reserves into Bitcoin would indeed be ridiculous. It was their mistake to build up a huge stack of essentially worthless currency and it looks like they are committed to correct that as far as possible in the time they have left until Western currencies approach their intrinsic value: Zero.
I doubt that the PBOC is in Bitcoin. It is just that the Chinese people see the writing on the wall just as the Chinese government does and a small percentage of them buys Bitcoin.
As a result, Bitcoin moves East, just as everything else.