Not really. The Borg already knew of the Federation because of the Hansens' expedition (which was about 10 years before the Enterprise-D encountered the Borg) as well as the subspace message sent by the remnants of the First Contact Borg when encountered by NX-01 (which should have reached its Delta Quadrant destination at about the same time as the Hansens were assimilated – it's a bit inexact since the subspace message was sent in 2153 and would take "about 200 years" to reach its target, and the Hansens encountered the Borg in 2356). So what Q did was warn the Federation about the Borg (in the guise of taking them down a peg by showing them a much superior foe), thus giving them a fighting chance.He caused a lot of death, though. The Borg found the Federation because of him.