It is Always posted on the first day in the Carnival Capers and in a handout at embarkation where a person should go to make dining room changes. It always states a time and place where you will find the Maitre'd to make the changes.
You are correct. the other thing that is always posted is the events of the day. It would have told them bingo would be played in that lounge at that time.
I agree something is just not right with this post. It is hard to believe that that much could have gone some wrong.