TikTok doesn't need to demonetize videos. They just adjust their algorithm to never show it again and it's effectively the same thing.

Does that prevent users from seeing a video from someone they follow?

I haven't used tiktok in a month, but right before I left lots of creators were complaining that their videos weren't getting as much views anymore, specially some that mentioned political stuff and the obvious thirst traps.

That essentially becomes their demonetization strategy, if you say things tiktok/ad sellers don't like, you stop being recommended. Youtube on the other hand at least separates their monetization from their recommendation system.

Do they have that? I’ve seen that TikTok just shallow-ban that kind of videos.

You mean shadow ban?

Ohh sorry, yes I mean a shadow ban