>>19537863From what WWE revealed themselves, which could be all kayfabe but it's really the only source of information
TKO wanted Rock to show up at Elimination Chamber because ticket sales were down, and the Rock said he would only show up if he was involved in a big angle otherwise it would be a waste. He didn't specifically want Cody to turn heel, even though that was his first pitch, another idea he had was to have KO win the WWE title and be his guy
Then some guy throws out randomly, what if Cena turns heel, and they go with that as the big angle, out of nowhere
Travis Scott also got involved because his agent knew a guy in TKO and they put him in. At some point it's very clear though that something fell apart backstage with the Rock and we have no idea what happened, but it derailed the entire heel run
