Let’s see, a thread that is late about 10 years since AH closure and it tries steer toward sensitive subjects at the first unrelated opportunity… Yep. 
Auction House ain’t gonna come back when blackmarket’s influence was so bad over Diablo 3 along the years. Allowing any type of item trading will seep into real money exchanges as digital payment sites are widely available now.
The moment it’s allowed, bot influence will grow and game never would be the same again. Community would split about trading and self-found in then Blizzard would have to take drastic measures to keep both sides happy which no one would be satisfied.
It maybe a hard to accept but it’s gone.