Star Trek: 10 Things We Now Know About The Temporal Wars
8. Khan Shifting In Time
The effects of the Temporal Wars play out across the entire breadth of the franchise, as in their nature, they don't follow a single line. This has accounted for the changes that have been experienced in established history, such as the life of one Khan Noonian Singh.
'First' encountered by the crew of the USS Enterprise in 2266, that version of Khan was an adult male, genetically engineered, having escaped Earth in 1996 aboard the S.S. Botany Bay. While the Kelvin universe would follow a largely similar origin story for the despot, Tomorrow And Tomorrow And Tomorrow displayed just how much had changed in the Prime universe.
La'an Noonian Singh was drafted by a dying Temporal Agent, finding herself forced to work alongside an alternate reality version of James T. Kirk, transported to the 21st century, in Toronto.
There, she encountered a child - her ancestor, Khan. The changes in the timeline, this time by Romulan agents, ensured that Khan's despotic era of the 90s never occurred - as he hadn't been born yet. Not in this timeline, at least.
This was foreshadowed in Farewell, when a defeated Adam Soong examined the folder labeled 'Project Khan' - dated 1996. However tangentially, this involves the Soong family with the Temporal Wars as well - a result that has ramifications that may yet be felt in the franchise.