I think it indicates that the religion has a lot of alcoholics in its midst, which is hardly surprising, such a closeted lifestyle is enough to make anyone turn to drink, and it's one of the few vices they have that isn't explicitly prohibited, yet
They successfully banned smoking in the 1970s, so I wouldn't put it past them to try banning alcohol outright at some point in the not-to-distant future
There's some serious holes in this obviously made up story
There are a couple of gaping holes that almost hurt my brain
If no one at all was drinking then why would the chef be impressed with them in particular, wouldn't he be impressed with everyone? And for that matter why would he be impressed with them to begin with? Not drinking alcohol is not some kind of impressive act, in fact statistically speaking, the majority of people don't drink
But it's all beside the point because when you go to a restaurant you never see the chef, they're in the kitchen and have no contact with diners, what a fucking mental story