Volition explained to joystiq at pax east that Saints row 4 isnt just saints row 3.5, and that work on saints row 4 started two months before saints row 3 finished, and a splinter team went and worked on the Enter the dominatrix expansion.
"We had to go in and totally gut the [Dominatrix] story for Saints Row 4. Everything that was the missions or the story we did for Dominatrix was totally thrown out," Steve Jaros, creative director at Volition told us. "All the voice recording that we did all thrown out. We redid the entire story. The game is mission wise the same length as Saints Row 3, plus other open worlds on top of it."
and then the story goes on to say that when jason rubin joined on the agreement was to combine the saints row 4 team and the enter the dominatrix expansion into one project,
"Everyone on the team had the same concern, we didn't want to make a 3.5, we aren't making an expansion pack. What we put out to the world has to be worthy of the name Saints Row 4. I really think everyone on the team will stand behind it," added Jaros. "So much stuff has been changed and thrown out. Even the best of the [Dominatrix] stuff that we liked and pulled into the game we still changed. Nothing was drag and dropped in."
and i mean, According to Jeff and Ryans twitter, the game looks awesome, and at the end of the day thats all that i think should matter.