Thanks, everyone for your replies.

I figured I'd try my luck here as this board seems to be more active, and I've noticed people from AA posting on JAL asking the same question about upgrades on JAL for AA elites. And yes I misspoke and should have said operational upgrades.

So it sounds like slim to none, which seems to be the case for any OW elite riding on another OW airline that's not their own airline.

Sounds like with the exception of lounges and EQM while using partner OW airlines, there's not much to the OW alliance.