I can literally hear bronzebeard talking to me in the timewalking dungeon…
Someone commented it was probably an April Fool’s day prank. Their theory was it was an addon, as some of them are famous for that kind of thing, but I wouldn’t put it past the Blizzard devs either. (The main thing that makes this seem unlikely is how the devs have scarcely enough time to do their jobs, let alone code in an elaborate prank like this.)
ETA: This Reddit post says in their case it was the GTFO addon.
https://www.reddit.com/r/wow/comments/1jp06pg/best_addons_april_fools_jokes/
Yeah, apparently it’s the GTFO addon
it’s not funny though, he already tortures us enough in delves… 
idk if this is worse or the year ELVUI decided to swarm the interface with hello kitty
Then you shouldn’t stand in that!
Also you can get rid of Brann if you type /gtfo options and uncheck the “April Fools Day Joke” option.