While Walters is rich, that doesn't necessarily mean he's liquid for that debt. And even if he is, they generally don't come out of pocket from other ventures to pay off MLB debt (though it seems that's what he's getting in trouble for now). And while I agree with you that Walters definitely could, I'm guessing the LA Dodgers debt will ultimately be handled by the LA Dodgers.
I guess this makes sense. So the Dodgers sign Ohtani to a $70MM AAV. They defer the money so the luxury tax hit is much smaller. Then they take the $70 they owe Ohtani, pay him $2M now, then take the other $68M and invest it in ways rich people invest money, which means the gains will outweigh the interest that accrues on the payments. So that when the money is due, they'll have more than enough to not only pay Ohtani, but also pocket some extra cash.
Is this the idea?