When this started it caused a lot of drama. The game mode is now back.
Heroic Tavern Brawl works a lot like Arena. You pay to enter and play trying to get 12 wins. The difference is you make your own deck from the cards you have. This does ruin the fun for the free to play players but it does bring the more competitive scene to people who generally wouldn’t be able to play competitively.
The rewards are exactly the same as last time. The image below will show you what you are playing for.
Good luck to any of you who plan to compete next week!