Dispel Magic: Dispels magic on the target, removing 2 harmful spell from a friend or 2 beneficial spell from an enemy.
Cure Disease: Removes 1 disease from the friendly target.
What I would like to see
Cure: Removes 1 magic and disease effect from the friendly target.
Dispel Magic: Dispels 2 beneficial magic effects from an enemy target.
Priests already have a pretty big toolbox and many spells to bind as it is. Yes this is the same number of spells, but in a PvE situation, very rarely are you dispelling more than 1 magic effect, so dispelling 2 off of a friendly player is unnecessary. Having 1 spell to do your defensive dispels would save the healing priests out there a keybind/frustration. I really think this would be the right thing to do with these spells.
Or how about this?
I think that all healers should be allowed to keep their separate cleansing spells in their spell books, along with the combined one. Then defensive cures could be combined into a single spell but healers would still have the option of using separate, non-combined cures. This would satisfy PvErs while also helping out PvPers. Tying defensive dispel to the other cleanses forces healers to not dispel when they're in bad situations like Aff lock + Rogue beating on them, or Shadow Priest + Rogue eating them alive.