they’ve done a fair bit to divest them selves from china at this point. If
As a Chinese company, that's impossible. That's kind of like saying Mojang has done a lot to distance itself from Microsoft. Microsoft at the end of the day calls the shots whenever it suits Microsoft to do so.
I suspect the main reason so many establishment politicians are terrified of it is because of how it suggest content.
That's the biggest issue for sure. It's the recommendation algorithm. You can use all the data you use for marketing based on feeds that people have followed to algorithmically create a sort of psychological profile.
Once you have that, you have a weapon because you can spoon feed an active user through radicalizing content. YouTube did it accidentally for years (though this has largely been fixed from what I've seen recently).
The CCP could do it intentionally and as they have the final say over anything and everything that happens at ByteDance, that's a huge risk. We don't need the millions of TikTok users being subject to an information psychological warfare operation.
They don't care too much about the data, though that might be useful to them as well. I think that's why they went along with protect Texas. They can still get the data out into China if they really want some of it. However, their main goal is influence and a direct line of communication to a large number of Americans.