There is no way to predict what might happen.
What *I* would find upsetting is being "told" what I should or should not be doing in regards to anything in my marriage. I'm also pink-flagging his mom's behavior here as potentially codependent, DESPITE her knowledge of alcoholism from the addict's POV. I personally think it's up to YOU to define your boundaries - not his mother. More will be revealed, but the way they are running roughshod over you & acting as though the AA program alone can save him..... it has my radar up, more will be revealed.
I would keep my expectations extremely low & work on understanding this disease & creating boundaries for myself if I was you. Even if a miracle occurs & it all goes perfectly & leads him to sobriety & true recovery the potential for relapse is a constant factor for both or you. It's just smart to be educated & aware about as much as possible - good luck!