Yes, AA won't extend an invitation to its own elites, even top tier ExPlats, to spend time in AAdmirals Clubs unless they have a membership or a paid first class ticket. The exception is international travel. This is quite unlike JAL, which treats its elites much better in terms of lounge access. However, JAL's First Class lounges are still only for paid first class ticketholders.

I don't think there's any question that JAL will have to grant reciprocity to oneworld elites for access to its business class lounges at least. But it will be interesting to see whether they admit top tier oneworld elites to the JAL First Class lounges. We'll see. It'll be more than a little strange, though, if as a JAL Diamond I can enter another oneworld airline's First Class lounge when flying JAL but I can't enter my own, "home" airline's First Class lounge. For example, if I'm flying NRT-HKG-NRT in JAL Y, does this mean I can't enter the JAL First lounge in NRT but can enter the Cathay First lounge in HKG on the return? That'd be weird. Even weirder if there's a Cathay First lounge in NRT.

It's going to be a mess lining this up. JAL has "too many" lounge levels compared to most/all oneworld carriers. And the JAL Global Club is quite odd as a parallel elite recognition program, so who knows what JGC members will get. I'm very curious how it'll all shake out.