Travel insurance will not provide coverage if you are bumped from an overbooked flight.
Typically, if a flight is overbooked, the airline will ask for volunteers to get bumped to the next available flight and may provide compensation to those volunteers.
If you are involuntarily bumped from an overbooked flight and the airline arranges a flight that gets you to your final destination within one hour of your scheduled time, no compensation is required, according to the Department of Transportation.
If you are involuntarily bumped and arrive more than an hour late, the airline must pay you 200% of your one-way fare, with a $650 maximum, according to the DoT. That amount can increase as the delay time goes up.