Then why are details of the NX-01's missions in the USS Defiant's logs (lost in TOS: "The Tholian Web") in "In a Mirror, Darkly"? If ENT were from the nuTrek timeline only, the Defiant would have looked like the 2009 ship and TNG in "These are the Voyages" would have been completely unrecognizable.
Plus, Seven of Nine mentioned the Borg's attempt to stop First Contact a couple of times in Voyager. Retcons and coninuity errors aside, it's all supposed to be the same timeline.