This is not new behavior between the two countries, the only thing new is the direction. US is finally waking up to the foreign soft power being exercised inside our own country, and it isn't benefiting us.
Google was operating in China until 2010 when they got banned because they stopped censoring search results. Other Western search engines like Bing continue operate in China.
GMail continued for a few years after that - I'm not even sure if it was ever actually banned, or just suffered the same fate (death by a thousands timeouts).
The domestic companies lost some attention share to TikTok sure, and a ban or domestic sale would generally be in their interests, but it's not like they were about to be Myspaced. They've remained among the most valued companies -- presently and in forecasts -- even while it was "eating their lunch"
It hasn't been an overnight switch, but the trajectory did not look good for US companies. TikTok was even eating into TV viewing time. There's a fixed amount of attention and TikTok was vacuuming it up from everywhere.
Where? Stockholders have been vocally livid about it.
We should treat social media as the addictive, mind altering drug it is, and stop acting like a free market saturation of them is a good thing.
China having their more potent mind control app pointed at the brains of hundreds of millions of people is not something to celebrate.