it's not the first time protests like this.. or even violent (relatively speaking, no one died) ones have achieved their goal. off the top of my head

- 2019, a city near hong kong: protests over local officials lying about building a crematorium instead of a park. Central government officials stepped in, gave amnesty to all involved, and ordered all medical bills to be paid by the state.. and I think the construction was cancelled.

- early 2010s: protests in Guangdong province over the removal of Cantonese programming from state tv. I think the change was delayed, and now, with online streaming, not a big deal.

- 2004ish: protests over a migrant worker who died in detention because he didn't have his paperwork to be in a different city. turns out, the detention centers were part of a policy from the state council and a law was never passed by the NPC to make living in another city without paperwork illegal. the supreme court unofficially ruled that the policy may be unconstitutional without a corresponding law. The policy was rescinded.