The official Disney•Pixar YouTube channel has just uploaded a Mother's Day inspired Monsters University trailer. The video says, "Mothers - at home or on the road, they'll always be your biggest fan. Happy Mother's Day from Disney•Pixar's Monsters University". As a flashback - if you remember, they did a nice tribute like this for Brave as well (posted below for reference).
Here's last year's Brave Mother's Day tribute as well.
Pixar Post - T.J.