Vince McMahon reportedly showed up at around 4pm ET on Tuesday and decided that he didn't like the show that was written, so it was re-done. Vince reportedly made several changes after 4pm, which is why the Daniel Bryan "career-altering announcement" was delayed again, and why WWE Hall of Famer Shawn Michaels did a MizTV segment instead of commentary as advertised.
Regarding Corey Graves missing this week's SmackDown, word is that he was filming a WWE Studios movie in Vancouver, according to the Wrestling Observer Newsletter. Renee Young is believed to be filming the same movie this week. As noted, Byron Saxton missed the show due to his father passing away this past week. Michael Cole and David Otunga worked commentary with Tom Phillips on the show, and SmackDown Tag Team Champions Big E and Xavier Woods helped.
As noted, this week's SmackDown episode from Miami was the first that saw new Executive Director Eric Bischoff sit on on the production meetings. Bischoff was reportedly seen spending a lot of time with members of the creative team as well. While Bischoff spent time at the meetings and with the writers, The Observer reports that he had no creative input into the show itself, at least as far as any of their sources could tell.