Lemmy.World is still awaiting that upgrade to 0.19.6 to make use of that change in the codebase (release notes) (actually now 0.19.7 is already out too, having come less than a week after the former, and representing just a few bugfixes, release notes).
On the other hand, 0.19.7 still has a picture issue: https://github.com/LemmyNet/lemmy/issues/5196
To be, the issue was never that no major instance was USA-based, location of the servers doesn’t mean much nowadays. It was more about the fact that no large instance was geared towards USA citizens (a la Lemmy.ca, as we discussed), with a message such as “a USA instance, for USA citizens, but everyone is welcome”. That hypothetical server being hosted in Canada or Europe wouldn’t have that much of an impact, it was more to be able to have politics, finance, news discussions related to the USA in one place