I'm not surprised to hear that he's going to multiple meetings every day. If he's not working and on medical leave, what better way to fill your time but with recovery efforts? I know when I was on medical leave during an outpatient treatment program, I was very sensitive about what I was doing with my free time.
Some people, working or not working, go to multiple meetings every day just to ensure they won't be drinking instead. The first months of recovery are very difficult and breaking daily patterns is part of that. If he was drinking in the mornings he might feel like he needs to break that pattern by going to meetings (or exercising or whatever). And if drinking after work and all night long was something he did, going to a meeting or two at night instead takes up his time and he certainly won't be drinking.
For many people in early recovery, meetings are a huge comfort. When we're sick with a cold, we take great comfort being in bed with a loved one taking care of us. Recovery can be the same way, with the meeting providing those same helpful benefits.