So thinking of First Contact,
When the Borg go back in time, using the logic here, they didn't alter history, but rather created a New Timeline, and because the Enterprise was caught in the Temporal Wake of the Sphere, they were sucked into that alternate Timeline. Then Picard and Company created yet another new timeline when they followed the Sphere back through the Temporal Portal.
I only half-jokingly suggested in another thread: This means the Borg Queen was just trying to escape to another timeline so she, personally, could have a do-over.
As for how the Many Worlds interpretation gels with the Temporal Cold War, it doesn't. But I'm fine with assuming that the TCW factions come from another alternate future, where everyone has a learning disability when it comes to temporal physics. We can call it Braga Syndrome.
