That is definitely a good point. But I get the very strong feeling from reading it that there's more to it than that, particularly because
Roy didn't know his little brother was in the LG afterlife. Additionally,
Windstriker will be able to visit Miko, and while I'm not especially knowledgeable about fallen paladins, would she even be in one of the Good afterlives? I'd interpret this as meaning you
can visit other afterlives, but
Elan's song seems to say otherwise.
In any case, I don't think the fact that Roy's family is in the LG afterlife quite explains why it seems to be presented as the "highest" one (whatever that means).