The film directly references Star Trek: First Contact
with the Phoenix, Star Trek: Enterprise
with the Enterprise NX-01 model, and the episodes "First Flight" with the NX-alpha/beta model and "Home" with the offshore stadium.
I go with what the film writers say - that it was one timeline which branched in 2233 and events prior to that are shared. The excellent novel Department of Temporal Investigations: Watching the Clock
explains it and other Trek time travels in detail, and the author most definitely did his homework
That said, it's all fiction and open to interpretation. I can see how it may have changed the past, although as a fan of ENT and the novelverse, I like to go with their version of events. It's cool to think that if Pine's Kirk went back to 1986 he may bump into Shatner's Kirk, or that any number of versions of people from possible futures could come back (like we saw with Admiral Janeway in Voyager's finale)