Watch the bad feelings if the passenger is expecting a good deal and then get to the airport and find out there are no seats available except full fare Business class.
He he... you would never find me complaining in this situation.
As for the MCO MLL, I'm guessing that because they have a much larger percentage of "families" travelling through, they might need to hold to the rules more strictly. I know there have been several reports over the years that most RCCs will let in *G's and their families.