The Joseph hatred is palpable here, but I think that's mostly for his off the field behavior. He is the Trysten Hill of the secondary.
I don't see it as a blessing for the team that Brown got hurt, but it is certainly a blessing for Joseph. The silver lining in the cloud is the Cowboys get a chance to see if Joseph can learn from experience. So far, in the few opportunities he has had to play, he has given up receptions and a few TDs because he has no idea how to play the ball. I think this is a lack of experience, and confidence. But he has shown he has the ability to get on the hip of a WR and stay there. In some ways he is the same as Brown, only with a lot less experience. I don't think many receivers will run by Joseph unless he gets fooled by doubles moves, which he will as an inexperienced player. But he does have great recovery speed.
In retrospect, maybe the Cowboys should have drafted Asante Samuel Jr. But my guess is they liked Joseph's 4.3 speed (he also ran an unofficial 4.28) and height. Samuel was clearly more polished than Joseph coming out of college, but with Lewis, Diggs and Brown already on board the Cowboys always knew Joseph would not have to play right away. We should also keep in mind Diggs had his ups and downs in his first year starting at CB.
What we will see now is if Joseph can turn his physical tools into football skills. We should expect some mistakes by KJ, but look for improvement over the rest of the season. If we don't see any, then the Cowboys will know they need to acquire another starting CB or two in the draft and free agency.
Nahshon Wright has had a few chances to play and has not looked very good at all. Unlike Joseph he has shown little ability to stay with receivers. Whether we like KJ or Wright is irrelevant at this point because it is likely both will see a lot of playing time. We better hope Diggs does not go down too because playing with 3 backups at CB would be a devastating blow to the defense.