They must be separating the meals in some way now.
In the past year or two, on F in LAX-SYD/MEL, I've had my main meal not long after departing LAX.
At least a couple of hours prior to landing, I've for whatever reason felt like having a second main for breakfast and have been told no, it's "too late". More than once. Sometimes I feel like (and plan on it before departing) having the breakfast menu, sometimes not.
I suppose the "old way" meal refrigeration lasts for a certain time only - I can't make sense of that, so someone please enlighten me!