Hmm going pop? I guess (Roc Nation thing), but Tim and Pharrell didn't have to go a pop route, they've been intertwined in commercial/pop music their entire career. They didn't go "pop."
Also, for Mustard to even be in a discussion with them, he'd have to make less predictable beats. Basically, if someone can replicate your beat on Logic/FL Studio, then you got some work to do. I just think of that Sanctified beat where Kanye & Mike Dean basically took his typical beat and slowed it down a ton and made it a hit.