I don't know exactly where the Cowboys would play him, but Anthony Brown and Byron Jones are both set to be FA in 2020, Chidobe, Lewis and Woods in 2021, Minkah 2022.
This allows you to not have to overpay someone because you don't want to lose a contributor on your defense without a guy to take his place, and also allows you trade one of those guys like Brown or Lewis this year.
Not a bad situation to be in if you go after Minkah even if it cost you a 2nd round pick because Jones and Brown if they hit the FA market will net you a 3rd and 4th round Comp pick.