I heard them talking about this a few weeks ago also. It was mentioned that his endorsements in Japan would likely be much higher if he signed somewhere as the only Japanese player rather than a team with Ohtani, which...makes sense
Of course, if depends on what he ranks higher in importance. Clearly the teamwith the best chance to win is LA. The team where he can play with his idol/mentor and still have decent shot at post season play is SD. The team with the highest endorsement potential is likely Toronto, but easily the lowest real shot at winning over the next 6-7 seasons, but you can still squint and see some positives.