In my early 20s I actually went to AA meetings over the course of probably a year. I kept it very secret, as I did with my very problematic consumption.
It was a group of probably 15-20 people, most aged 40-70. I was by far the youngest there. And let me tell you they would not have appreciated someone coming in who is under any kind of influence, including marijuana (even if it had been legal back then). Some people smoked cigarettes but even that was kind of frowned upon. At some point I mentioned that I have been getting into non-alcoholic beer, and even this was controversial, because I allegedly was masking the behavior and a slip back to alcoholic beer is easy. With that same logic, any kind of coping by using alternative drugs is just redirecting your addiction. In the group there was a strong belief that you are an addict for life and that you have an addictive personality type. And at least to me it’s kind of true. As a side note: Nowadays I am drinking sugary lemonade as a treat (something I would have never done in my 20s) and a fuckton of specialty coffee. For me, this is ok, and it works. But I understand if in their philosophy this is not a good way to go about your problems.
Anyway, at another point someone else asked about benzodiazepines to ease the first transition. This has also been controversial, and while you can get this prescribed when you are becoming sober, everyone recommended not to do it. There seemed to be a strong belief that the best (or only) way to go about your addiction is to rawdog sobriety - don’t mask, don’t cope, face your feelings and pains and reasons for your consuption. Only then can you move on, forgive yourself, ask others for forgiveness, and all of these famous steps.
There is also a clear rule that you come sober. Although this is specifically in regards to alcohol, I am really sure any other mind altering substance that numbs or excites you would have led to you being excluded from this week’s session.
Now, this is my experience with one group outside of the US. Also, I was a very shitty member and should not have been there to begin with. I made a joke, a competition out of it, I’m not even sure why I kept going there. I went there drunk, but no one ever suspected anything. The paramedics hardly suspected anything when I had 3.5%o blood alcohol, they assumed I had a slight migraine. I went to AA with literal booze in my handbag just for the thrill. I did so in university and relationships and with my family, and I was always so successful, I think I just wanted to see how far I can push my behavior before someone notices, before someone stops me, before I fuck up.
I stopped going to AA because I went abroad, but it was just a great excuse to stop going. The truth is I wasn’t ready to stop drinking quite yet. Committing to never having alcohol again when you are missing the one thing in life that you have actually wanted and you’re just 22 is just really hard.
Tl;dr: I would not recommend marijuana use in AA groups, to be honest neither during/before, nor in between meetings. It might not be the community you are looking for if you want to cope with your addiction by using an alternative drug. Whether or not it is a smart or sensible thing to do might be up for debate, but from my very limited experience with AA this would neither be ok for the group, nor go with their philosophy.