Originally Posted by
Fabo.sk
MdC is not a position, rather a "rank" or in other words a job title, so that is not assigned per se.
In other European carriers I know it's customary to select positions in order of seniority (at the briefing), but under pursers authority to change as necessary. I do not have any direct reference to LX though.
To my knowledge this is true for LX as well. Important distinction is I think for first class you need to qualify. MdC = Purser and see Swiss job offerings:“You can progress to Maître de Cabine, Instructor or First-Class Cabin Crew Member after just one year”