Sure Strad, I'm sure well run successful organizations allow their players to have input on roster construction. This is not wise even for a player of Ohtani's caliber, maybe with one exception and that would be a preferred catcher for him.
It does happen occasionally in other sports, if you have a Tom Brady, Lebron James situation where Brady wants a certain receiver.
And how slippery is this slope? What duration of his contract does he get to have input on roster construction?