It's a great way to go about it too considering that Void Elves are all about 'control'.
Plus, WoW's always had Light/Void have a sense of duality. Ashbringer was created from a very dark shadowy object. Naarus can change states between Light and Void.
Plus Tauren Paladins are 'lorewise' Sun Druids. Paladin is just the gameplay aspect of it.
Could always make VE have some 'void knight' but it plays as Paladin in gameplay. Especially if class skins happen.