Lemmy was made by communists, seeking to build an alternative to Reddit where communists will not be able to be fully censored. Federation also is similar to how the USSR was federated, and FOSS attracts the left. As such, many areas on Lemmy are going to be pro-CPC (and supportive of socialist states in general).

This isn’t the case on every instance, though. Each instance has its own political leanings, some very anti-China and anti-communist in general. It depends on the moderation, federation practices, and focus of the instance itself.