I saw this option on my DFW-DCA flight this morning. (I cleared the upgrade on yesterday's outbound at the 100-hour window but didn't clear today's flight until ~28 hours out.) So I decided to pre-order the breakfast sandwich, on the assumption that that way I would have one available for me in case they might otherwise run out. (My presumption was and still is that if an EXP pre-orders a BOB meal for Y, it will be provided without charge--why would they charge?)

But then I cleared the upgrade, so I pre-ordered kale pesto omelet.

So here's the funny part: I'm currently on the flight, and the flight attendant says, "Sir, it looks like you have pre-ordered a cold breakfast sandwich. And you have also pre-ordered the regular eggs. Which would you like?" Obviously I'm going with the hot meal. But I find it interesting that the upgrade & re-select doesn't erase the previous order.