I always read on the dis, that Disney doesn't do this anymore and that if they do it's only 1 snack credit for a CS meal.
Every year we go the first week of Sept., and every year we exchange MANY CS meals for snacks (3 snack credits = 1 CS meal). We have done this at every resort we've stayed at (ASMo, Contemporary, Pop). We have never had a problem and just last year, the CM's would always ask me if I wanted to use a CS for my 3 snacks or if I wanted to actually use snack credits.
While, obviously it could be totally different this upcoming year (everyone swore you wouldn't be able to do it last year, but we did no problem) and perhaps I'm just really lucky at the resorts we stay at, I certainly expect to be able to do the same again this year.