EXPLAINED: John Cena's Heel Turn, How It Worked & What Really Happened (WWE News)
WWE planned John Cena's Elimination Chamber heel turn for at least "six months".

WWE didn't rush into John Cena's industry-shaking heel turn at Elimination Chamber 2025 last weekend. In fact, according to Dr. Chris Featherstone's sources, the company agonised over every detail (major and minor) surrounding Cena's turn on Cody Rhodes and alliance with The Rock in Toronto.
Triple H and pals left nothing to chance. Featherstone's sources told him WWE treated the shocking booking move as "a long term decision and that it took planning and time to think and propose the perfect moment to do it.". Further, the promotion's bigwigs contemplated the turn "easily for over six months" before pulling the trigger on it to kick off March.
This wasn't some knee jerk surprise that somebody proposed earlier in the day then. No, it was something that had been chewed over for a long, long time during creative meetings. Big questions likely included: 'When is the right time to do this?' and, 'Will fans even accept Cena as a heel during his own retirement tour?'.
Big green ticks, the Elimination Chamber event and the word 'yes' (for the second question) apparently went up next to both of those. Even so, there was an element of risk and WWE knew it going in. That's why they wanted to "make sure they had 100 percent of the scenario" locked down, which included picking the right sort of crowd who'd furnish Cena, The Rock and Cody Rhodes with the right kind of reaction befitting such a monumental shift for one of WWE's most iconic characters that'd surely even rock other wrestlers backstage.
Elimination Chamber Was Handpicked Deliberately For Cena's Turn

Elimination Chamber wasn't chosen because it happened to be the next PLE on the calendar either. According to Featherstone's sources, the Toronto show was picked out (after WWE "evaluated for several, several months") because it was a big time stadium show in Canada that'd play in front of a raucous live crowd. Rewarding that loyal fanbase up north with such a landmark occasion will surely pay dividends for the company later on too.
The fact Chamber was the last major pay-per-view hurdle before reaching WrestleMania 41 also played into WWE's thinking. They knew Cena going rogue would shake things up and add a lot of spice to the final lap before full attention turns to Las Vegas. In other words, Triple H, The Rock, Cena himself and the WWE creative team at large painstakingly pored over every story beat to ensure the turn was as impactful and surprising as possible.
All of that hard work was worth it in the end.
Some are even comparing Cena's heel turn to Hulk Hogan's back on WCW's Bash At The Beach 1996 PPV. That shocked the entire industry, led to the nWo boom, and quickly turned WCW into a bonafide WWF/WWE-beater. Obviously, WWE sits atop the biz in 2025, but it's a good sign that they're keen on rocking the boat every so often - that'll keep viewers on their toes.