So, I understand Zandalari having to wait until 8.1.5. They don’t officially join the Horde until after the Battle of Dazar’alor. They’re allies of the Horde but not members of the Horde until Talanji and Sylvanas make a deal after Rastakhan’s… incident. However, Kul’Tiras joined the Alliance at the end of Kul’Tiras questing in 8.0, when Jaina was officially passed leader by Katherine and ratified by Lucille, Pike, and Tandred. So, is there a reason Alliance have to wait until Horde get Zanda…
Kul’Tirans are already on the Alliance.
Zandalari are not on the Horde until after the raid.
Ion outright stated that although the Allied Races will always come in pairs, Horde and Alliance will not always get their Allied Races at the same time in the future, but apparently he only meant that when the Horde will get theirs first.