That's why I said "not that I know". The parent comment said that people may speculate that someone who refuses to drink might be alcoholic, but there are also people who don't drink for religious reasons, obviously. In any case, people can decline a drink for any reason at all.
But that's the key part "more likely", and not something definitive. It's the thinking that that inference is definitive is where it crosses the line from trying to be understanding about another culture to becoming a racist argument.
I agree though that its definitely flirting with that dangerous assumption.