According to bitinfocharts, the hashrate topped out at 171 EHs on May 14, and bottomed out at 83 EHs on June 23, a drop of about 51.4%. Also according to bitinfocharts, the current hash rate is about 87 EHs. Obviously all these figures are estimates, and there is the potential that variance influenced all or some of these figures, but it is undeniable that a very significant portion of the network hashrate has been recently taken offline.

From the looks of it, there is a good chance we will see difficult decline by the maximum 25% the next change period, although it may not be quite that much. Some of the decline may be attributed to the price declining, but I think the overwhelming majority of the decline is due to the CCP seizing mining equipment throughout China.

Given how much production of ASICs is done in China, along with the above, I think there is a non-zero chance that a single entity (the Chinese government) that is hostile to Bitcoin has or will have mining capacity that is greater than 51% of the total hashrate. It is possible that the CCP has not seized all of the mining equipment that has been taken offline, and that some of the reduction is due to mining operators turning off their machines and attempting to move them out of the country so they can continue using them.

I believe you are referring to pools based in China, which is not the same as miners based in China. A miner with equipment in the US who is mining on a pool based in China will move to a different pool if the pool shuts down, while a miner based in China will stop mining if the Chinese government shuts down its operations. With that being said, I do think that more than 50% of the total Bitcoin mining capacity is based in China, or if not, an amount very close to 50%.