It's meant as a joke of sorts, not a migration. From the NYT:

"Sure, there are the people calling themselves “TikTok refugees” and joining Xiaohongshu, a Chinese social media app, as a half-joking protest of the U.S. government’s decision to ban TikTok on national security grounds. (The joke part is: OK, Congress, you want to stop us from using a sketchy Chinese social media app? We’ll download an even sketchier Chinese social media app and use that instead.)"

https://www.nytimes.com/2025/01/18/technology/what-if-no-one...

https://www.nytimes.com/2025/01/16/arts/tiktok-red-note-chin...