Beyond revisionist history.
Nobody, I mean nobody, said at the time he was drafted up until last week that this was a redshirt year.
Maybe this isn't obvious to you, but it seemed obvious to me that both Collins and Crawford would be ahead of Hill on the depth chart in 2019. Of all the DT's, only Crawford and Hill are under contract for 2020. I just ASSUMED it was obvious the Cowboys would play the veterans this year, while allowing Hill time to develop.
It was also blatantly obvious to me that they overdrafted Hill based on his talent, not his refinement, and that further refinement would be necessary. If so many other DT's had not already been drafted ahead of him, I think Hill may have been picked later. He's a 3rd round talent drafted in the 2nd round because of the laws of supply and demand - meaning the demand for DT's was higher than the supply. The rumor (don't ask me for a link because I don't have it, but I think the Chiefs and Patriots were both interested) that I read was that there was another team planning on drafting Hill either late in the 2nd round, or early in the 3rd. So, if the Cowboys waited to draft Hill in the 3rd round, he likely would not have been there.
This, of course, is no guarantee that Hill becomes a good player. The Cowboys traded for Jihad Ward, who was about like Hill, a DT overdrafted in the 2nd round by the Raiders. Ward only lasted 2 years in Oakland, before coming to Dallas, and getting cut at the end of training camp. He's now on his 3rd team - the Colts.
Do I believe Hill was overdrafted? Yes.
Do I believe the Cowboys could have waited to get him in the 3rd round? Nope, some other team would have overdrafted him instead.
Am I convinced Hill will become a good starting player for the Cowboys? Nope, not yet
Do I think he has some raw talent that COULD lead to a big win for the Cowboys? Yes, but there are no guarantees.
I tend to give Will McClay some benefit of the doubt with his track record...