Didn't the interpreter also say that Ohtani had no knowledge of it, and the interpreter claimed he didn't know he'd done anything wrong? Nothing about the stories makes any sense at all right now. MLB not being interested in it suggests to me that they knew about this well ahead of time and the betting didn't break any MLB rules (so Ohtani's probably safe on that front).
It feels like Ohtani probably made the bets, didn't realize they were potentially illegal, and he got caught in the investigation. The interpreter (who probably did the legwork) takes the fall, scuttles off to Japan where it's unlikely he's extradited for an offense like that, and probably keeps getting paid by Ohtani for looking after the house or something.