In my experience there is something beneficial about having a different context review and prompted differently, but it's not used very well in practice. Your previous context does create its own blind spot, but you're also getting at a problem in non AI reviews which is "what am I reviewing for?". Some companies like Google have traditionally had very tight guidelines for what a PR reviewer is supposed to criticize and what not to worry about, I don't think AI code review is much different on this topic