Restrictions have already lost all sense since all classes can collect the same sets which don’t look like anything.
You can buy tons of sets which all look like cloth, some looks like leather, and some looks like garden gnome or a half nude Hawaii tourist, remember those covenant races which armor sets fit ALL classes and all races? yeah those also exist.
Locked behind label: class armor? Hurr durr, here some BOE drop that looks EXACTLY like supposedly unique class armor piece.
So, I don’t see why you won’t lift class/armor type restrictions.
I like to mix armor on my toons, but I always stuck with unavailability of some fit waist or shoulder that could fit my idea which is from another class or type armor. Or I want to build something that my class doesn’t have because … why?
Weapons. It’s so funny that you can mog all melee weapons into artifacts that can be different type of weapon. But you still cannot mog daggers/wands into anything except daggers/wands. Why? Well wand I can understand. Since it’s ranged weapon (which never used as is because there are many other spamable abilities dealing much more damage, and I don’t think anyone cares that a wand projectile will fly from an axe or a staff).
B-but, you don’t understand! If you could t-mog everything into everything the class fantasy is ruined! You won’t be able to tell…
Oh, shut up! You already cannot tell who is who with what we have in the game. I just told you already that anyone can be a garden gnome, a pirate baron, a Sylvanas incarnate (with a quiver) or an aviator within ANY class or race. There is literally no class consistency with armor ALREADY, so having old restrictions is just nonsensical.
I understand restrictions of race sets (heritage) cause it’s kind of lore-oriented stuff. But there is literally no point to have other restrictions anymore. The same way there is no point to not have raid questing for a group that you are in, but here we are still doing nothing while raid is gathering, when you can do few world quests a while but that’s another story.
So do the right thing and lift restrictions. From everything except heritage armor (and maybe from class armor if you want that so much). It’s the only thing that is sensical today to have uniqueness.