There are plenty of liberals from the PRC, especially from the big liberal cities such as Shanghai. There are still a whole bunch of NED funded media/social media accounts in the mainland in general.
In my experience meeting such classmates they're not that different from some of the HK/TW international students as they all tow the same line.
I have met a few that are not liberal, however my thought here is always, why would they chose to come here, Some for the international understanding, but moat will chose a place with an ideology they think will align with them
One of the main reasons might be the fact that some of the highest ranked universities are located in the US, UK, Australia etc.
Competition is quite intense in the mainland and usually a degree from a university from these countries will add some prestige to their resumes (sometimes we refer to those as 'plating it in gold').