Technically, I don't know that thy brought him in for the redzone in its entirety. Most likely, they were referring to the last five yards.
If I was on a defense against the Cowboys and Zeke came in when the ball was on the 15 yard line in the redzone, my first thought is "pass" and he's there to block.
It's not like he's going to head for the sidelines in an attempt to outrun containment. Also, I wouldn't have to be cautious about his ability to escape tackles. He's not exactly the most elusive RB in the NFL.
The Cowboys linemen are not cohesive enough to pull off an effective screen in such a congested area.
So basically, unless it is a goal line situation, Zeke isn't a very effective weapon in the redzone these days. I would probably go with Luepke before I went with Zeke. I'm not bagging on Zeke, I regret having to come to this conclusion.