So I have been thinking about this situation, and it is a fascinating situation with how the Texans have gone from up 24-0 on the road in KC in the second quarter of the league quarterfinals last year, to out of the playoffs, star WR gone, head coach fired, 4-12 record, and your franchise QB wanting out of the franchise, all in just over a year's time.
So the group of agents that represents Watson also represented Earl Thomas and Jalen Ramsey, so they are adept at playing the holdout game and are not afraid to play hardball. Since Watson's request for trade has nothing to do with his contract terms, and he is only making $10 million in salary this season, I do think he would sit out the whole season in 2021 if he is not traded. If the Texans want to play hardball with Watson and not trade him, they have a big problem if Deshaun is willing to sit out the season. The Texans won't know for sure he is willing to sit out the season until next season comes. If they then realize they won't have him for the season and decide they want to trade him, what they can get for him is far less than if they traded him before this years draft.
I think Casserio is a smart guy (and I don't know this, he could be like most of the people who leave the Patriots who aren't nearly as good or as smart as when they have Bill Belichick and Tom Brady working with them), and if he has any power within the organization, he will see that the above is true, and he will trade Watson before the draft and get the maximum value for him. If Easterby has the ultimate power on the team, I can see the Texans taking the hard stance, keeping Watson until the season starts and then either trading him for far less than they could have gotten before the draft, or holding onto him as he holds out for the season, and then trade him next offseason. If the latter occurs, I have a hard time seeing the Texans winning more than 3 games in 2021 without Watson and without any high draft picks, big free agent signings (they can't afford it) and probably without JJ Watt who they will move this offseason for marginal compensation and to free up some cap space. So the Texans will have wasted a year of rebuilding. They are truly a crumbling franchise with an incompetent owner who has put his trust in a faux Christian guru who has no discernable skills and yet seems to have authority over all the decision making.