Sure, but there's a difference between having the potential to do something, and actively doing it. I'm aware the FBI/CIA can get my data from Google if they want it, but something would have to trigger them into wanting to investigate me. With a Chinese company there is no "if", all of the data goes straight to the CCP. Tencent, the bloated multimedia company, even had a moment of ironic hypocrisy where they didn't want to give away all of their users' data.
At least in theory they have to get a warrant, although there are plenty of examples of tech companies handing over information without one. They definitely have access to all the same information if they really want it though.
Edit: In hindsight I think I may have misinterpreted how that post was intended. American government agencies do have a harder time getting access to TikTok's information, although at least for US users TikTok has separate servers that make it possible for them to do so.
This is what people miss. Furthermore, it's reasonable not to want an enemy state to have access to information relating to a country's citizens. Yes, the US has done. Yes, it was wrong. Yes, they are getting a taste of their own medicine. That's why they're worried about it. They know how badly that information can be used.
Furthermore, it is clear the Chinese government has an influence over app contents. It is easy for them to use it to shape the opinions of their userbase depending on the country.