Actually, protein from raw eggs is only about 60% bioavailable. In cooked eggs it is over %90. It is a common myth that raw eggs are healthier than cooked, probably literally perpetuated by Sly Stallone in the Rocky movie lol.
Pretty well known that cooking helps humans digest many foods. Should raise no eyebrows with that claim. Unsure how applicable it is to our birds, though heat treatment is definitely beneficial in reducing the adverse effects of some components in legumes - so it holds true at least some of the time.