Just got back from 2 SFO- MIA trips. I'm a silver and was 100% upgraded through LAS.
Both of my outbound flights were red-eyes. But there were empty F seats on all legs except maybe one.
There was no food except beverages and snacks. (Note that there are no alcohol pre-flight bevs allowed in Florida).
Geez, it would be nice to be served something more than a candy bar and some peanuts in F on a 5 hour flight! (Luckily I always carry my own food... just in case.... because of dietary restrictions).