John Cena

John Cena was not the part timer in 2016 that he is currently and Big Match John had battled in a Six Pack Challenge on the first episode of the show. Cena was feuding with AJ Styles during that time and so he was not booked to win the match and become the #1 contender.
Cena has reduced his WWE appearances considerably and the 16-time World Champion made his return to Smackdown just last night where he teamed up with Becky Lynch to take on Andrade "Cien" Almas and Zelina Vega.
Look who just shut down all of Tony Khan's critics! More HERE.
Dolph Ziggler

Dolph Ziggler emerged victorious in the first main event of Smackdown as he defeated 5 other men to be crowned the new #1 contender for the WWE title.
Ziggler had an epic rivalry with the Miz after his feud with Ambrose. However, the ShowOff is now a part of the RAW roster and is mainly being used as WWE's gatekeeper for the upcoming NXT talents.