I'm not familiar with US/JP copyright laws. But in my country (Taiwan), there's a clear separation between copyright "property rights" and "personality rights". Even works that have lost copyright protection will only have lost the "property rights" associated with the work, but never the "personality rights", which are perpetual and untransferrable. The personality right is basically your right to claim that you are the author of your works. In that sense, it feels as if things that end up in public domain can still be said to be "of a third party".

I'm not a lawyer, so I may just be confusing myself with a non-issue. But excatly because I'm not a lawyer, I'd like the only opinion that matters on this forum, i.e. official response, since no other player account has a verification of qualification that I can rely on, so who knows if someone's argument is really that of a copyright lawyer or if it's just another keyboard warrior like me thinking we know everything?

Hence, please, an official response.