Honestly surprised at the responses here.
If you want it, buy it (if you don't - don't) - agree.
But AA absolutely should be preventing/policing people from moving themselves to MCE if they aren't entitled to / haven't purchased it.
This:
Originally Posted by
ty97
AA should do a better job of policing self-upgraders. Regardless of it not being a separate fare class, it is a separate product for purchase, or free to elites. I have no issue on full planes when standbys are put in MCE (it only makes sense to do so). But on a non-full plane, self-upgraders should be turned back to their assigned seat.