Recommend adding dungeon maps for easier navigation. Helpful for new players mostly.
I think this goes against the joy of exploration gameplay. Especially for new players.
A large part of the joy of seeing a dungeon for the first time is figuring out the layout. Not knowing what comes next. Personally the wow factor of seeing a cool room with special mobs or decorations would be strongly lessened by having seen the name/layout of the room beforehand.
Dungeons should be explorable, and adding maps would make it harder for Blizz to have secret or out of the way areas that you can stumble on if you take your time.
Adding a map doesn’t make it any less “explorable”
Knowing which way I am going makes me more eager to explore the dungeon. Even with a map I still get lost on some complex layouts.
Also, they still can find different ways to put secret stuff there. They don’t have to add it to the map. Imagine seeing an unmapped corridor, imagine it just abruptly ends. That might make you want to go there to see what lies beyond, with the added bonus of giving you a sense of direction.
They can also add fog of war to the maps similar to the world map, unlocking it as you go along.