Light and void are likely coming packaged together, but would you consider Army of the Light doing bad stuff on Azeroth with the Scarlets a "cosmic" expansion? The only thing not happening is a retread of the Shadowlands idea of the expansion taking place entirely in another realm.
If Blizzard wanted to cross out things at the same time, the way to do it would be an Old World revamp/Dragon Isles as the new zones that features aspects of Light/Void/Life.