We know the Cowboys have changed up their receiving corps. It feels like they are looking for good route-runners who will be in position when Dak Prescott progresses through his reads. This appears to be a very important thing for Dak, who operates a little differently than Tony Romo did.
Part of the Dak-friendly movement has been to find receivers who will be in the right spots at the right times. With run-pass options, receivers have to be precise with their routes and their timing. That was not a strength of Dez Bryant, who had some of his success with Romo based on reading and reacting.