There's no huge reason to bring them to the US. Plenty of US corporations have maintain overseas offices. Even if its impolitic to employ them directly in China, you can employ them in other offices (for example, Amazon has been known to do this with their Singapore offices)
This thread is largely pointless political back-and-forth were predictably the comments with a more positive opinion on current US immigration enforcement will be flagged.
To get back to the original point, personally I doubt sentiment on US immigration enforcement would be so significant a deterrent for Chinese talent, who may not share the political views of the American left for whom this is a big concern.