#2 AJ Styles wanted “Beat Up John Cena” merchandise
AJ Styles, Luke Gallows, and Karl Anderson enjoyed beating up John Cena so much in the summer of 2016 that they repeatedly said the phrase “Beat up John Cena!” at every opportunity in their WWE promos.
Speaking on his Mixer channel in 2019, Styles revealed that he wanted the phrase to be printed on a new WWE t-shirt. However, after presenting the idea to Vince McMahon, the WWE Chairman explained that it would not be good business to sell merchandise that tells fans to beat up the top good guy in the company.
#1 Heath Slater wanted Dean Ambrose in his WWE rock band

Heath Slater said on E&C’s Pod of Awesomeness in 2019 that he asked WWE producer Michael Hayes in 2012 if he could start his own on-screen rock band with Dean Ambrose, Fandango, and EC3.
Hayes said Ambrose and Fandango could not join the group because WWE already had plans for them, while EC3 was released from his contract shortly after Slater made the suggestion.
In the end, Ambrose became a member of The Shield and Fandango made his WWE debut with a victory over Chris Jericho at WrestleMania 29.
As for Slater, he ended up receiving Drew McIntyre and Jinder Mahal as his new allies to form The Three Man Band (aka 3MB).