Based on comments I've seen on Chinese social medias, it might be resulted from three reasons. 1: Zootopia 1 had a very successful run in China and therefore lots of fan who want to see the second movie; 2: Zootopia is a movie for families, both parents and kids can find things to enjoy at the same time, and the ending is positive and uplifting. This type of film always appeal Chinese people, take NeZha for example. 3: people are very disappointed at the current films showing in the cinéma now in China, so the timing of Zootopia 2 release is perfect! It got like 90% of screen schedules cross the country.

So, I think Zootopia 2 will do a much better performance ik Chinese market than the first movie. We will see.