We were just on AD for both Christmas and NY and had no problem whatsoever booking our BOGO meals. In both cases they allowed us to use our second BOGO later than day 2. It does seem as though Christmas and NY seem to be the big "holidays' that have limits to dining options but we are booked on AL over Valentine's Day and there is something in their dining packages about a special holiday meal so I guess we'll see how that one goes.
Special note about our recent Christmas and NY bookings on AD. Not only did they allow us to use our 3 day dining package AND our BOGO over these holiday sailings, but we were able to dine right along with those who paid the big bucks for the special "holiday meal" menu. They seated us on either Christmas Day or Christmas Eve (can't recall at the moment) with the "regular" Chops menu and those who had paid extra had a separate menu and whatever additional dining options they were entitled to. There was really no difference. I had been afraid that they wouldn't allow us into the restaurant at all on Christmas Eve or Christmas Day but on AD, at least, there was no problem at all.
I agree, @nelblu, if I had been told "no" to using my BOGO I would have taken it ALL the way to the top. I think that's absolutely WRONG and EVERYone in the management chain on that ship would have heard from me...