Say someone is insured with Safeco or another preferred market and...

Say someone is insured with Safeco or another preferred market and indicates that there is no knob and tube fuses in the home since it has been updated to circuit breakers. They have a fire claim and it is discovered that while there is a circuit breaker box, the wiring was still the same wiring that was connected the knob and tube. Would this preclude them from receiving coverage? I am having concerns as I do not have a way(at least