A “gotcha” I just discovered: even though the selector uses radio buttons (which usually means you can only choose one), this is a multi-select list. So if you don’t also choose English (and/or other languages you understand), you’ll miss content that does have a language tag.
Designing UI ain’t easy.
~~I get a 404 error when I try to view that community from my home instance, but it definitely exists… I suspect it’s because the community has no posts at the time I’m writing this, maybe federation doesn’t work without any?~~