For a longish (but not transcon) domestic FC flight on Friday, I picked one of the two additional "limited availability, only over 24 hours in advance) main course lunch selections shortly after receiving the email. All seems good, However, I noticed that when I went back into the "pick your meal" IT to remind myself what the other choices were, I no longer see limited availability options. The flight is five days from now.

Does one really need to pick immediately in order to guarantee that both of the additional choices will be available? I've never noticed anything like this before, although most of my pre-order meal experience is from D1 flights.

To give a bit more information, FC looks fairly full on the seat map and it's a fairly important segment from a hub, but it's not a primarily business travel date and the destination airport shouldn't be particularly elite for DL. I'd categorize the destination airport as mixed business and leisure.