Said wiki page is aiming to provide a list of all the imagery sources available in JOSM. All listed sources there should show up in the ‘Imagery’ menu if you’ve downloaded data in the ‘correct’ region.

I looked at the tree mentioned by @SomeoneElse, but the ‘Örebro’ imagery did not show up ‘by itself’, even though it has a border in which it should be loaded.

But if the layer is added via the route that Andy mentions, everything works fine.