Twitch addons now has a selector for retail or classic World of Warcraft installation. When the classic selection is chosen, Twitch update for DBM downloads the retail version instead. The end user then gets the improper version message upon login to the game and has to manually correct.

Nothing I can do on my end. you'll have to open a ticket with twitch about that.

heck i don't even have that feature on my end. on mac side, my client supports retail and only retail, it doesn't even support ptr.

Actually i was able to get mac client to see classic version of game and definitely see same bug, but yeah I still can't do anything about it. Twitch has to fix this.