Does it matter in which countries the offices with the staff who develop some of these models are? I think so, for a number of reasons too long to go into.

Re "US citizens only", the question I'd have right now for all the AI companies is: can any new better-or-as-good-as Fable AI model actually be released?

If not, stop development of better models. That's the single most expensive thing any of them are doing.

Export controls on software is somewhere between "hard" and "impossible", so "US citizens only" means something between "nobody" and "perhaps some government agents", but the latter don't pay enough to justify the cost.