There is indeed a Horde version of this, it’s a part of Zandalar Forever!
And just like for Alliance to complete the end stages of that you do need the three zones completed on the one character.
So ideally you’d want to do a full run of the Horde story on at least one character so you get all the stages done, which would be part of unlocking Zandalari Troll Allied Race. Not sure if that was a goal of yours but if you were going to be doing the Horde story anyway might as well make you aware of it 