This is just a rumor for now, but it’s a very interesting one worth mentioning. Word on the street is that Monsters, Inc 2 is actually going to be a prequel. Check out the excerpt form a Disney catalog.
“will take us back to before a time when Mike Wazowski was top comedian, before James P. Sullivan was top scarer, even before the buddies joined the MI workforce. In fact it takes us all the way back to school — the University of Fear to be precise. Although the two start out as frenemies, Monsters, Inc. 2 will weave the tale of how the dynamic duo transition from rivals to BFFs.”