They're talking about the only shot of the group that matters in hunting; the Cold Bore
You should sight in for your cold bore shot
Yes, good barrels should have the cold bore in the group. Still, making daily trips to the range and firing a single round at a paper target will tell you lots about your rifle and load
I understand about the Cold Bore Shot.
Question: You have a real 2 MOA rifle, and a real 1/2 MOA rifle. Day after day, which one is more likely to place the CBS dead nuts center?