Everyone wants to bring up the Gruden trade. What other examples are there? Different times. Also, Loomis has a relationship with Payton and will likely not hold him hostage. We are getting nothing near that return if Payton returns to coaching.
Loomis isn't going to try to "wrong" Payton, but Loomis' job is to take care of the Saints first. Payton also knows this as does the rest of the league. If a team is willing to wait years for Payton to be a true free agent, good for them. If Payton wants to wait years to be a true free agent, good for him. But any team that is going to want Payton next season knows at least one first is going to be absolute minimum... and if it isn't and Loomis moves Payton for less, he should be fired immediately.