It's got nothing to do with meal priority. SE and VIP get meal priority.
In your , she didn;t ask you last.... be it by chance or whatever reason, so that;s fine, and she didn;t mention any issue at the time of your order.
The issue is that she should have simply told the other passenger that the meal wasn;t avail.

I imagine in the back end of operations they can already see days out that the upgrade list is massive, thus catering for full load i would ithink.

Chalk it up to poor staff.

Writing in for this... i wouldn;t bother.... not worth the already known response