Believing in his good morals, the underlying hope might be to achieve change through subversion: If YC becomes popular in in China, people might visit news.ycombinator.com and find very sane liberal thinking and many shocking truths about their country.
Much more likely that anything negative about China will be deemed political, like many other subjects have been in the past, and flagged off the site. That is largely how the Chinese Internet works anyways.
Reddit was blocked by the Chinese firewall this month. The suspected reason is discussion of the Uyghur concentration camps. Shocking truths don’t last on the Chinese internet.
When YC is invested in China they won’t last on this website either.