Castellanos definitely needs to recover and be something like a 1.5 WAR player to be tradeable without picking up 99% of the contract (which won't help the AAV). His is just the salary to move because he seems more replaceable than Schwarber who is probably a better fit for 1B post-Hoskins anyway.
They do not HAVE to do this of course. They could always just eat the salary and if Rojas wins a job then great. A team can survive just fine being over the luxury tax threshold. Especially if they have fewer free agent needs which come with draft penalties.
I guess the one thing we do not want to happen is for the team to block young players. I don't think Nola does that though it does setup Wheeler to be more likely to leave when his contract is up, hoping 2 or 3 of the young pitchers are rotation mainstays by then. We also should probably be setting up Bryce to be the 1B after the Schwarber and Castellanos contracts are done. Our second organizational strength is actually in the OF after starting pitching. We have lots of possibilities with Rojas and then Crawford, Boyd, De La Cruz, and Rincones. There is some depth that some of them should develop. Lee could also go in the OF though he seems a better fit to replace Bohm in the lineup if Bohm does not improve. Now, Bohm is a fit when he is inexpensive, but if the defense does not improve he may not last through his arbitration years.