Unless you're Bobby Bonilla, the Mets, or a generational talent like Ohtani who can ask for whatever he wants, players don't really have a choice.
It likely wouldn’t work in any of the salary cap sports (definitely not NHL), and even for baseball it seems like he has the right set of circumstances to make it a reality.
Dead years aren't new. Teams are often looking to lower their cap hit, so I don't know why they'd have a problem with players adding dead years or deferring payment. I just don't know how they are taxed with jock laws, though. Does it go based in the schedule of the seasons they actually played in, or the dead season when they aren't even on the team? Or does it avoid jock laws altogether and get taxed like income which is unrelated to play?