Nope, I simmed a few seasons while controlling all teams with CPU roster control on for all but one and never saw anyone get put on the trading block. You don't have to draft for every team, but the draft will stop on every team's pick & then you can sim the pick.
I was more interested in controlling all teams to change their coaching tendencies (less blitzing). However, while the NFL isn't exactly like MLB, I'm not sure I can enjoy playing a franchise with zero CPU trades.