As you said those stamps do show up on the other sites but when searching for other items that are more likely to be on other sites sold by local sellers, your items do not necessarily show up. I could have missed your listings but when I did a quick search in the stamp category on .au for merino sheep, I didn't find your listing or when I searched for the 1924 olympics or the 1924 olympiques in the timbres category on the .fr site, I couldn't find your listing.
I've noticed the same thing with my listings. If the international site has a number of local sellers with the same search terms my items won't come up. If there are no local sellers with those search terms some of my items may come up under the international seller category but that isn't guaranteed if there are many other international sellers with the same items.
I don't know if the page that the OP refers to is current, accurate, inaccurate or something for the future but to me, the info there does suggest that international visibility will be changing.