I have no inside friends providing any inside information, so take this for what it is worth: Any conversation about having a coach hired that will not take over until after the 2021 season is just incorrect.
In the first place, you cannot hire someone at a public institution that is planning to start in a year and nobody know about it.
In the second place, and we have seen this time and again, too much can happen in that year to either of the coaches involved. If Pruitt, by some miracle of miracles, went 10-2 next year, he would not be fired. If Chadwell went 10-2 next year and was on everyone's list to be hired, who knows if he would not want to take a job somewhere else. What would happen if someone UT really wanted also expressed an interest in coming that was better than Chadwell, like say, Hugh Freeze, or Tom Herman or dare I say it, Jon Gruden? (no, I don't think Gruden would ever be interested)
I am not suggesting Chadwell should not be the coach. But he, nor anyone else, is going to accept a job that does not start for a year.
I think it is safe to say that Pruitt will be fired before there is a coach hired. It may happen in the same day, but certainly not a year later.