Hadn't really thought about this before... Do accuracy results "work" if a squadron fires at an enemy squadron with a defense token?

Yes they do.

The only results that Squadrons ignore are Criticals , both For and Against, unless there is some other rule in play.

This is how Bossk kills squadrons with Scatter

They also work against ships, which is insult to injury on a B-Wing that just rolled a hit/crit on the black die.