I suppose the same could be said for the direction that Enterprise, and later JJ Abrams Star Trek, took.
I tend to think that a new timeline was created before "Broken Bow", for there are so many contradictions between Enterprise and the first four series in what was established. One example comes to mind when I think about Vulcan.
From "Balance of Terror":
War is never imperative, Mister Spock.
It is for them, Doctor. Vulcan, like Earth, had its aggressive colonizing period. Savage, even by Earth standards. And if Romulans retains this martial philosophy, then weakness is something we dare not show.
Based on this, the planet Vulcan, prior to Surak, expanded into neighboring systems with a warlike vigor. We see this implication in Nemesis, where it is implied that the colonizing descendants of Vulcans conquered another species.
For a species that valued logic and peace, they do have a mean streak of specism. (Is that the right word?) Some of their people viewed humans as "barbarians", a term that Spock once referred to his species once in the third season. (A consistent contrast in Star Trek since the beginning has been the duality of barbarity and civility.)