What makes this "the key difference"? I think you can safely say the same about Chinese tech companies. VPN usage is higher among tech-literate people for obvious reasons, and while having access to uncensored information doesn't necessarily instill love for the US, wanting "bad things to happen to the United States" is a pretty extreme level of nationalism.
I wouldn't be surprised if Chinese tech employees in China had a more positive attitude with respect to the US than Chinese tech employees in the US, due to "the grass is greener on the other side"-type effects.
Maybe we should focus more on decreasing that baseline so we can actually figure out if foreign companies are doing bad things to the US out of malice or indifference?
Why would Tiktok need to maliciously harm the US when just their simple act of seeking profit is already doing enough work to harm the US without the need for any malintent? It's like wondering if the open sewer dumping into your town's water supply might also have gluten in it when you're gluten free.