I'm sorry, but other than the move at 4m 33s I don't see anything to contradict my impression of how he did.
He gets forward, sure, that's basic to his role in the team. But in the video he repeatedly arrives too late and ineffectively which is why he doesn't receive a pass.
Look, feel free to disagree with me, but no one should be surprised when Blackett is moved on.
Perhaps this sounds harsh, but for me the real question is whether he will end up in the Premiership or in the Championship. Given his left foot, athleticism and eagerness to learn, I'm optimistic about him being a Premiership player down the road, just not with Manchester United.