i dont see this happening anytime soon. there is an arena bot atm and it's kind of buggy as well, while a naxx bot seems even more complicated. its just my opinion but i feel like playing naxx manually is actually pretty fun.
I think Naxxrammas is a nice way to learn everything If you will bot HearthStone since u started, u will never learn how to be better at it You don't get nothing from Heroic except challenge, and it's not bad luck. You need to be wise. I win the first boss 5 out 5
Naxx is really awesome to learn different mechanics. If anyone remember Dead mans hand in the ol'MTG magazine InQuest.
Maybe, if you have a cards to choose your strategy, but if you are beginner - there is no way to beat them. I think everybody can beat them after, to learn some strategic steps.