I think 'For all paid users in the United States' is clearer. I live in America, but not in what the United States considers 'America', so I do not get to use this new feature yet.
Using America as a shorthand for "USA" is hardly limited to people who live in the US.
Apologies, I updated my original comment, I missed that completely.
Might you be able to use a VPN to visit the US (safely!) for a short while? Not sure how Anthropic geolocks.