To directly answer the question, Rednote is not generally used outside China, and the point about these apps being representative of "global" social media apps is false.
https://www.vice.com/en/article/chinese-app-rednote-hits-1-i...
It's called Dispo. You probably haven't heard of it because it became almost irrelevant a few weeks after launch. #1 on the app store doesn't mean a whole lot.
It may not retain all the new users, but it is not going to become irrelevant.