With the optional account linking I believe Steam will probably allow those countries to buy again. They should all still be able to play currently, they were just facing a stonewall of not being able to play in July had Sony continued down this path but now it will be optional.
Like others have said on Reddit, all Sony had to do was just say "Hey if you sync your account you can get a cape" and a lot of people would but nope instead they wanted to just force the player base into it instead.
XI Wiki



