The reporting I found (from the Verge) was that an employee of TikTok (in America) would email spreadsheets to executives in China, and other similar cases of US employees having the actual access to data and passing it along to other folks in China.

This all suggests to me that the 'Operation Texas' technical controls were actually in place and pretty good (or dude in China would have just run some SQL himself), and what isn't in place is hard process control to prevent US workers from emailing stuff to China. Which, you know, is exactly what Congress could pass a law to deal with.