Simon Pegg said:
Sure, we experience time as a contiguous series of cascading events but perception and reality aren’t always the same thing. Spock’s incursion from the Prime Universe created a multidimensional reality shift. The rift in space/time created an entirely new reality in all directions, top to bottom, from the Big Bang to the end of everything. As such this reality was, is and always will be subtly different from the Prime Universe. I don’t believe for one second that Gene Roddenberry wouldn’t have loved the idea of an alternate reality (Mirror, Mirror anyone?). This means, and this is absolutely key, the Kelvin universe can evolve and change in ways that don’t necessarily have to follow the Prime Universe at any point in history, before or after the events of Star Trek ‘09, it can mutate and subvert
Also, from Star Trek Online, the official continuation of the Prime Universe. In reference to a new quest line that lets you travel to the Kelvin Universe:
The sheer destruction from the Hobus supernova has weakened the barrier between our reality and one strangely similar to our own, leaving a strange temporal anomaly in its wake. This anomaly serves as a gateway between our universe… and a quantum universe both similar and different to our own.