I've been watching the holiday flights (Xmas, North East to Florida ) for buy-ups or even outright paid fare upgrades. They seem to have blocked most buy-ups to F as well as displaying no F seats available on their MD flights. If I do a dummy booking the F seats show all are available but the fare jumps to $1600-$1900 RT which of course is so unreasonable for the routing that nobody is buying it.
I am guessing that maybe they have not yet figured out what aircraft and routings will be available months from now and prefer not to encourage bookings in F until it gets sorted.
Any other ideas?