I actually think it's naive. Sure if military personnel or state department use TikTok that can create security risks, but the same is true with any other social media network.
The additional data that TikTok tries to gather from the mobile OSs is insignificant compared to what you can get from videos that people take willingly.
Russian soldiers use VK, that doesn't stop OSINT researchers tracking them down on there.
Military personnel is not what this is about, it's about the data of all the citizens in the US. It's about manipulating public opinion, sowing divide or a thousand other options.
But shouldn't that concern go the other way? If the Chinese government is dictating content policies of TikTok, that should obviously be a concern, but I have not seen this alleged.
Granted collecting say interest data based on viewing figures would be a precursor (I suppose it's likely that TikTok could figure out if a customer leaned left or right politically). But again that's not what the complaint is about.
It's also hard to ignore that TikTok's responses are at face value reasonable (such as evaluating touch patterns to identify bots... that's obviously something they have to do given the predominance of bots on social media platforms).
I mean, TikTok can manipulate public opinion and access to information more easily than that, by simply artificially demoting/promoting certain content — no user data needed.
Even without the government dictating content policies, the threat is still there. Take how the Chinese government has addressed the exact same concern from their side. That is to say, they've banned US social media platforms like Facebook and Twitter and who's to say if it's solely because of the allegations that those platforms follow US government dictations.
A forseeable future is one where Americans are using VPN to access Tik Tok and then we see some government officials clamoring for an American version of the GFW.
The additional data that TikTok tries to gather from the mobile OSs is insignificant compared to what you can get from videos that people take willingly.
Russian soldiers use VK, that doesn't stop OSINT researchers tracking them down on there.