The upcoming edition of WWE Saturday Night's Main Event will feature the final match of John Cena's wrestling career. He'll face Gunther, the winner of the Last Time is Now Tournament.Cena wanted to showcase the future in the tournament as well as at the event, holding his final in-ring performance. Main-roster stars will face off against NXT performers on the undercard.With a rushed preparation outside of the 17-time Champion's final match, WWE made the next five mistakes with Saturday Night's Main Event.#5. Cramming it into two weeks after Survivor Series: WarGamesWWE scheduled the final edition of Saturday Night's Main Event for two weeks after Survivor Series: WarGames. While the build to the annual PLE went on, the Last Time is Now Tournament also took place on RAW and SmackDown.Navigating the holidays is always tough, but WWE has packed several events within short time frames throughout the year.It lessens the impact of focus if they're always promoting another event before the current one takes place. Sometimes, less is more.#4. Choosing NXT stars who were already featured at Deadline and on SmackDown View this post on Instagram Instagram PostJe'Von Evans, Leon Slater, Sol Ruca, and Oba Femi all competed at Deadline. Evans is one of the most featured stars and has appeared on RAW and SmackDown this year. Ruca competed on SmackDown.These stars are part of WWE's future, but officials could have chosen different names for Saturday Night's Main Event. It seems like favoritism instead of featuring more than a few performers.Thea Hail recently returned to NXT. Lexis King is being used on TNA more than NXT. The future will be filled with several talented stars, so only featuring the same names over and over feels like overkill.#3. Only four matches booked for Saturday Night's Main EventWhile there will certainly be loads of fanfare and faces from Cena's past throughout the night, only four contests make up the card. Along with Cena vs. Gunther, fans will see Bayley face Sol Ruca.AJ Styles and Dragon Lee will face Je'von Evans and Leon Slater. New NXT Champion Oba Femi will face Cody Rhodes.The event will stream on Peacock in the USA, meaning time constraints shouldn't be an issue like they were for Goldberg's final match. That means another match could be added.#2. A star of the future doesn't win the Last Time is Now tournamentWith the Last Time is Now Tournament, John Cena said he wanted to pay forward his final match to a young star who represents the future of WWE.Names like Carmelo Hayes, Bron Breakker, Austin Theory, and others fit that description since they're under 30. Most of the competitors were closer to 40 than 30, and a former World Champion, Gunther, ultimately won it anyway.The Ring General also already retired a WWE Legend, Goldberg, this summer. The honor would have done wonders for any of the aforementioned stars.#1. Using Cody Rhodes instead of another top WWE starCody Rhodes is WWE's top star, appearing on SmackDown every week as well as nearly every PLE throughout the year. Most other champions aren't afforded the same luxury and may only get two or three PLE appearances per year.The American Nightmare has been on SmackDown the past two weeks since WarGames, and will face Oba Femi. If someone like Sheamus had gotten the spot, it would have given Femi a chance to leave with a huge victory.Officials probably won't book its golden boy to lose to the champion of its third brand. Finn Balor should appear since his match on RAW was canceled.If Randy Orton had been present the last few months, he could have put someone over. The inclusion reeks of having Drew McIntyre break up the match or attack Rhodes at some point.