Strange optics not to mention the elephant in the room. I could see them hitting some roadblocks and wanting to try again to get into China, but that would be a reasonable thing to come out and say. It also would be reasonable to come out and say they've changed their minds due to political climate or some other risks. Instead its... the new guy is busy?
Why do you think it's political climate that changed YC's mind? With or without political climate being an issue, doing business in China is different and relies on of relationship building that takes a long time to nurture. It might just be hard!
Also recent developments of TikTok's business in US is also a red alert. If indeed the regulation extends to capital markets, then YC's US investors will put themselves against greater uncertainty of guarding their investments.
If the Corp US are smart and watching, they need to reduce/spin off/get rid of their Chinese ties as soon as possible, because they might have to endure long term consequences if the conflict in between two countries get worse.