the mainland minority

Mainlanders are a minority in HK. They are not native Cantonese speakers and if you have ever interacted with some HKers as a mainlander you definitely feel it. This is similar to, say, how Beijing natives would discriminate against waidiren. Locals hating on tourists is not uncommon but actively harassing them is bad and now it's part of this international geopolitical mess.

Good, the Uyghurs should dissent And flee after what has been done to them.

Do you know much about the Uyghur issue? Do you know anything about the history of Xinjiang? Why don't black people in the US just flee the US if they are facing discrimination? Do you realise how tone-deaf that sounds?