Use community programs to leverage free labor to remake old art assets (dungeon tier, vanilla quest rewards, etc) in appropriate detail for the modern game. You could have an almost constant stream of participants awarded with game time (or in game goodies) without tying up internal resources. Use public voting for judging/QA.
New artwork. Community outreach. Modernization.
Win/win/win.
I dont think labor is the problem when it comes to artworks and stuff
It’s resources. Of course, it would be great to update the entire item library every time they updated the graphics pipeline, but that isn’t feasible from an internal resourcing perspective. But, there are hundreds or even thousands of enterprising free lancers who would do the work for a bit of recognition, a star reference in their portfolio, or just for the love of the game.
Boy, this wouldn’t end badly at all
hidden ducks everywhere
but not actu… well you know.
I’mma be sticking ducks in places you didn’t even know existed before.
Those are called “mods”, and they already exist.
Let us create battlegrounds.
Considering it’d be the community doing this, I think you have a typo in there.
Get a better name and we will think about it
I have my own personal art portfolio of nothing but renderings of bracers.
They are my favorite armor piece and I always get excited when I get more! Especially the repeats. I always feel specially rewarded when they come back! 
Anyways, I would love to be able to provide them with MY versions of bracers and provide all the renderings they may need!! Even when they say, “we don’t need anymore bracers!!!” and I can smile and give them the choice of three more.
There’s legal reasons this can be problematic. While Blizzard’s lawyers would certainly make people sign an ironclad contract, even the best contract can have loopholes, never mind the expense Blizzard could potentially face if people challenge it even with no legal basis.
Imagine someone makes some assets, then a year later sues Blizzard for millions of dollars alleging that Blizzard did not provide adequate compensation. Even if they have absolutely no case, Blizzard will have to spend hundreds of thousands of dollars in legal bills.
Now multiply that by X number of players and you have a problem.
also most if all dont have that cash for an attrition for the long run
If it were as easy as that, the legal system would grind to a halt. All submissions would just become blizzard property (like AFV has done for many years). Other than needing to keep an eye out for hidden ducks, I can’t imagine there being any downside to this.
Blizzard won’t even allow the gameplay to revolve around player lead factions instead force us into NPC factions they control AKA Horde and Alliance.
You think they will give players a hand in shaping Azeroth?
It’s not a free hand, it’s just reskins. Obviously there would be guardrails.
As I said, they won’t even allow player factions. We are just along for the ride. You can forget about driver seat level input.
How to get hacked, 101
I honestly dont know why they dont do this. It should take 6 ducking years to make a battleground map. You could do it in an afternoon.
Probably fear of licensing or copyright risk.