don't know where you heard they don't serve alcohol before noon in Florida...we were eating breakfast in Florida on DD's 21st birthday in Jan. 2010 - around 10 a.m. When the waiter found out it was her birthday, he said we should stay until 11 a.m. when the bar opened so she could have her first drink there.
Anyway, I know mimosas were on the menu at the Kona Cafe for breakfast last year and I think they're on the menu at the Grand Floridian Cafe too.
Also, we've been in Disney restaurants before noon and had both wine & beer suggestions made by our waiters (just a couple of weeks ago at SciFi around 11:15 a.m. the waitress was pointing out the specialty adult beverages on the menu.)