Though the Nexus saga showed some of the cracks in the PG Era, it eventually became co-opted and fell back into line with the rest of the program.
It wasn't until June 27, 2011, that the deep fissures in the modern product became clear.
During a promo on Raw, CM Punk "broke the fourth wall" and the PG mold by: swearing, attacking John Cena, insulting the USA Network, criticizing WWE fans, and mentioning Hulk Hogan, Paul Heyman, Brock Lesnar, Colt Cabana, New Japan Pro Wrestling, and Ring of Honor by name.
The storyline continued towards the Money in the Bank pay-per-view on July 17. On that night, CM Punk defeated Cena for the WWE Title in a match that was universally praised by critics. After beating Cena, Punk supposedly left the company with the belt—an ultimate doomsday scenario.
CM Punk's promo and title win made wrestling history and catapulted him into the upper echelon of WWE.
What made CM Punk's promo so earth-shattering is that it reintroduced self-awareness to WWE, something that was common in the Attitude years and absent in the PG Era. It brought back some level of reality in the product, a certain degree of intellectual honesty that shows respect for the fans.
For that reason, Punk's promo and title victory were together the most recent "doomsday" to rock WWE.