My guess is this is new, not necessarily the deferring, but the amounts. It used to be pretty incidental in the overall numbers. Griffey Jr. is or was still on the Reds payroll, But when you're deferring 90% of he contract, that's clearly circumventing not only taxes for the player, but the overall salary restrictions for the team.
Now there are very few players who'd even agree to this simply because it behooves about 99% of the players to get their money when expected. Not let the team hold onto your money. It's why I said when pople make such a big deal about Bobby Bonilla's $1 mill he gets from the Mets, that's stilly on Bonilla, not the Mets. If Bonilla got that money back in the 90's when he played and invested it, it would be worth alot more than $1 mill per season.
My observation to guys like this, and certainly not Ohtani...."how much money do you need?" I mean seriously? What are we doing here? Many of these superstar athletes have more money than they or generations of their family can spend so why do you need that money? The union hates that ideal but at what point is it detrimental to your life and the organization? Someday it will end and like the NHL, the leagues will have to blow up the current CBA and start over.