#5 Should happen - John Cena and Becky Lynch participate in the Mixed Match Challenge as a tag team

The second season of the Mixed Match Challenge was quite underwhelming and if the WWE wants to maintain its Facebook audience for the inter-gender tournament's 3rd installment, they need to include the tag team of Becky Lynch and John Cena in the tournament.
Their tag team match was one of the most talked about matches of 2018 and so, the WWE Creative should not shy away from booking them as a tag team.
Cody Rhodes' uncle is a WWE Hall of Famer. More details HERE.
John Cena and Becky Lynch's tag team would definitely draw more viewers to the Mixed Match Challenge III and also keep John Cena around WWE for a few weeks.
The WWE can also book a dream final for the 3rd season between John Cena/Becky Lynch and Charlotte Flair/AJ Styles if they consider putting John and Lynch's tag team as a participant in the tournament this year.