I would argue they should have to. They scraped data off others, a lot of whom did not want that data to be used for AI training, and still had to share it with the frontier labs. It’s only fair they should have to hand it back.
The only way US maintains dominance over Chinese models is by having an ecosystem of models. Relying on a small set of frontier labs will only let you get ahead temporarily. I agree with Gary Tan on this one.
Generally companies are welcome to choose to who to provide service to, as long as it's not discriminating against a protected class, or ruled as anticompetitive (which is a very high bar in recent case law; even if the same 1890s-era laws are still on the books).
I don't think a correct remedy is to require companies to provide services even if they want to. A simple example: you drop a client because their asks / ways-of-working / etc is more headache and costs than it's worth. I've done that before, multiple times, in my freelancing life.