You heard it here first folks!
Insider source informed me that Arthas will be making a comeback in Shadowlands! He will be the new leader Alliance since Blizz wants to make PC people happy by gay marriage of Anduin and Wrathion, thus they will ride the rainbow(and each other) to the happy place, leaving guilt tripping Arthas no other choice but to take the reins of the Alliance and make it great again.
Theyre also working on relationship between Lor'themar Theron and Baine Bloodhoof, but therese no solid info on that, but it appears someone is quite solid at Blizzard atm, if you know what i mean.