My understanding was that even for a heavily deferred deal like Ohtani's, the difference between the yearly salary and the calculated AAV needs to be put away into escrow anyway. So it's not like any team is going to open up additional cash flow for themselves by doing one of these deals. The Dodgers' yearly cash flow for the deferred Ohtani deal vs. a no-deferral 10/460 deal would effectively be the same.
So even on the low chance that any other player wants to do an ultra-deferred deal like that... it's really not doing them or the team anything other than being able to announce a bigger looking number. There's no secret sauce here that would put the Red Sox at higher risk of being outbid by another team.
Here is a relevant quote from The Athletic explaining the situation:
"The Dodgers can’t actually hold on to all the deferred money for 10 years, though. They’ll have to start putting a lot of money aside for Ohtani no later than 2026.
'Deferred compensation obligations … must be fully funded by the Club, in an amount equal to the present value of the total deferred compensation obligation, on or before the second July 1 following the championship season in which the deferred compensation is earned,' the CBA reads.
The CBA goes on to say that “fully funded” means 'the Club must have funded, for the duration of and without interruption in each year, the current present value of the then outstanding deferred payments, discounted by 5% annually.'"
So basically the accounting structure allows Ohtani to have the *biggest* professional sports contract ever signed while still making his contract more roughly in line with actual dollar value predictions. But again, given his massive endorsements, he is maybe the only player in MLB who could agree to such a contract structure and....still be making tens of millions a year. I don't think this will herald in a new era of deferred money and even if it does, I see no reason to assume that Boston would be any less likely to hop on the deferment train than most other teams, aside from your regularly scheduled griping about ownership. If Boston misses out on a high value free agent and the Yankees sign him using a deferred contract, then we can worry but Ohtani is such a unique player in many ways that I can't imagine it becoming commonplace.
And on the subject of this possibly serving as a precursor to the Dodgers getting YY as well....to be honest, if YY doesn't sign with Boston, I'd vastly prefer him in the NL. (Also I live in LA, so obviously my opinions is slightly skewed).