He might do really well. He might drink again. Either way, what can you do about it? So why drive yourself crazy about it? All you can do is go to AlAnon and focus on your own recovery....the way you hope he focuses on his.
I say this because I lived through 2 outpatient and 2 inpatient rehabs with my RABF before he truly got sober. I learned that whether I fretted or not....didn't have any impact on his recovery...just made ME crazy. It wasn't until I learned to "stay on my side of the street" and focus on MY recovery...ie not HIS recovery.....that I started to feel better. I didn't ask questions, didn't ask about AA/counseling, etc. It wasn't easy at first, but it was the right thing to do.