Re: Did First Contact change the timeline?
The only prior contact with the federation was with the Hansen's as seen in Voyager. This would have introduced them to "us", but I doubt we would have been perceived as a threat, considering at the time the only people the Borg had assimilated were 3 civilians and one transport ship.
But they didn't just assimilate "3 civilians and one transport ship." -- the collective also assimilated everything the Hansens knew and whatever they could learn from their ship. While that still may not be enough to constitute a threat to them, it's a whole hell of a lot more information if they'd been taken by say the Klingons or the Kazon.
"You are the product. You feeling something. That's what sells. Not them. Not sex. They can't do what we do and they hate us for it."