Teams need to have decaying rating or MMR when not played.
Also since MMR can never seem to be fixed it would be nice to have the old arena system implemented. You play at your rating. Queing into people at your own rating regardless of MMR.
So many seasons ive tried to come back on my shaman who is 2500mmr and can't because even with honor gear once your behind a full seasons of epics you can't really compete against equal players having less gear.