confiscating Palestinian flags displayed publicly and preventing mobilizations in support of Gaza

I don’t really think the evidence is strong enough to attribute any sort of anti-Palestinian policy. The video is short, only 13 seconds, with no audio and no context. It doesn’t depict a large mobilisation of support, only one person, though it does look like he had his flag confiscated by school-security. In the clip, another person also has their Chinese flag confiscated. It’s possible given the evidence that large flags were confiscated regardless of which flag it is. We can also see a smaller Palestine flag allowed by the school-security.

The twitter account you attributed only posts unsourced and impossibly to verify anti-China news, so it’s possible this video is widely taken out of context given who’s reporting it.