The way I read it is that it's saying that it's important to make your own assessment of what relationship you want to have with drink/drugs. I didn't see anywhere that it promotes moderation, or abstinence come to that. I think it does say that it is a choice best left to you. And then, once you have made your choice, there is really little left to do other than live out the choice you have made.
I don't think it does say that happiness will somehow "come" if you stop drinking. I agree that that would be AV because if happiness doesn't come then you may well think "Well that didn't work, I may as well drink then." What I got from it is that if you feel that you have freely considered all the options that are available to you and made your choice then you will be happy from the onset and quitting will be easy in the sense that you have freely chosen it and so will feel that it is something that you really want to do.