Note that only one country has so far banned foreigners from using their models, and it wasn’t China.

When you're not in the lead, your best strategic move is to neutralize trade secrets advantages of the leaders. I think a strategic approach is being misinterpreted as a demonstration of virtuous ethos, which is crazy given (as the other commenter mentioned) the norm of secrecy when it strategically suitable in basically every other context.

China bans all sorts of things, so this doesn't really matter. I actually view it as a good thing. Americans get the best access to the best technology and we can go on to use it to maintain or gain a leading edge in the progress of our society and businesses. Why would we want to give that away for free so people from countries like Russia or China can build competing companies or use these tools to undermine our society's aspirations?