Two points.
1. (And I am jumping up onto a soapbox here). Replies that state only: "Nope. Never seen it" are pointless. Are you implying that because you've never seen it that it never happens? Or that the OP is lying? Or that the OP is exaggerating? Please see the first sentence of MikeandReneePlus5's response for a better way to approach this.
2. The topic here is "What happened?" which suggests that something has changed. I can't remember there ever being a time when CMs policed things closely. Perhaps the changes have been with the decorum of guests themselves, or perhaps the addition of both a Margarita bar and a Wine trattoria. Maybe some people are spending a bit more time enjoying "full on" drinking rather than "sampling". But people have been walking around with drinks, some of whom have overindulged, for as long as I can remember and there hasn't been any active policing that I recall. So maybe what has changed lies not with Epcot but with the guests. Or perhaps nothing has changed and the behavior witnessed is kind of a "one time out of twenty" situation and the odds finally caught up with you. (As it will, eventually, with all the "Nopes" out there.)