sidebar says unix is allowed and ios and macos are still unix. but this joke is so far from the theme of the community, you could change the ipad to a windows CE tablet from the 90s and the joke would still work. unix is just some background item here, casually mentioned
it would fit better in microblog memes or maybe math memes
They still support them, they are just not on the landing page. You could select them during registration, maybe not all of them but I remember the African one from last time I created an airmail.cc address.