I disagree on both accounts that the Rangers screwed up by not trading Hayes and Zuke at the last trade deadline.
I think many fans don't grasp the concept, the need and true benefit of having such players on the roster to insulate developing prospects from being put in roles roles they are not ready for. Chytil, Howden (and possibly Andersson at some point) are definitely benefiting in many ways. There's really not much to discuss, one either gets the concept or not.
Second, there is a lot of arguments that playoff hopeful teams are will willing to give more at TDL than in the offseason, even if there is a bigger pool of potential trade partners in the offseason. In this regard it didn't make sense to trade Zuke and Hayes even earlier - at 2018 TDL when the Rangers parted with Nash, Grabner and Miller at forward position. More supply = diminishing return.
Also, in terms of a trade value - most GMs assign values and go after specific players based on their overall reputations (as factors vs another factor being their recent few months performance). Looking at Nash's trade as a prime example of a reputation being a prime driver in spite of a poor performance even though a personal decline was a true reason for such performance.
If you trade Hayes and Zucc at the deadline last year you all but guarantee you don't receive fair value for them. When you flood the market, you lower prices. It is not a theory, it is a fact.
By waiting to trade them this year, you still run the risk of not receiving fair value but I think you are better off than if you trade them at last years deadline when we were doing a fire sale on the rest of the team. In theory, guys playing on the last year of a contract or a one year contract tend to perform well so their next contract is very fat - this would also lend to a nicer return in a tread. Hopefully Hayes and Zucc pick it up.
Even if we end up getting a late 1st rounder and a B prospect, I mean... history has shown us that more often than not, you won't receive a return like Sakic received on the Duchene deal. It is kind of expected, 1st + B prospect. Anything better than that would be gravy IMO.
This is why a few of us cautioned against a rebuild for years. In theory it works well and sounds great, kind of like communism. In reality, also like communism, it rarely ever works as expected. It is more frustrating, grueling and agonizing than the pretty image that people paint in their own heads.