I don't use or like tiktok, but that post also came across as super fishy to me. Lots of it boiled down to "I'm a software engineer, trust me" with a good amount of FUD thrown in (going on about GPS data when the app doesn't even request the Location permission? complaining the app can see your screen resolution?). I'm sure the truth is somewhere in between but tiktok is the beating-horse of the day so you'll see all sorts of cool stuff like mainstream media using an anonymous reddit post as a source.