The Mag’har/Au Dranei orc and the current orc have shadow priests. Orcs can’t use them because they never updated the race/class combos but orcs have had shadow priests since BC. The name Mag’har is what is problematic. They should allow orcs to not identify as such, let them use warlocks, let new identity tags be made, the maghar warlocks would use an identity tag such as hellfire orc, with maghar skin tone options and felscarred versions and access to those racials. How can you be Mag’har and say that when you are a shadow/void priest or dk… Again that little thing would let us make our customized tailored for a better experience. Orc warlocks got screwed over with customization.
That is what should be the retcon to get rid of this silly lore restriction imo. If they change the story maybe retcon some stuff for fun’s sake. Or write something like oh some hellfire orcs came with us and joined the horde then. I was suggesting a way to retcon them in.
They can also just make crossbreeding between the orcs a thing and culture mixing. So literally they do get mixed, start having relations with another, and fel becomes more socially acceptable to some participating members such as mages that would be interested in the stuff.