In the middle of the job? No question; the sub shouldn't. Long time after the job? No question; the GC has no role anymore. In the middle period (move in to 2 years?)... this is the potential time frame for a phone call.
The GC may be getting squeezed by a new contractor for that bonus room finish or an add on but if this were so then why didn't you get a call from that GC to do the wiring related?
This street has to run both ways.
Design-Build isn't supposed to mean design *as* you build.