I'm a little confused at this point, since I've been everywhere now, and the only thing I haven't done yet is actually participate at the Battle Tree. I returned to visit Prof Kukui, but all he gives you is Substitite. I've been to Aether Corp, and gotten the Beast Balls from Wikie and Type: Null and the Memories from Galdion. In addition to the scripted encounter with Tapu Koko, I've also caught Tapu Lele. I've seen everything on Melemele Island, and am working on filling in the other 3 islands in the local Pokedex. And I've caught several Pokemon using Island Scan.
By this point in previous games, I would have received the National upgrade to the Pokedex quite some time ago. Local Pokemon have a line on their Summary page for their Pokedex number, but the Pokemon caught with Island Scan simply do not have that line on the Summary Screen at all (OR/AS the number was replaced with ??? if caught before National Dex). And the strategy guide also makes no mention whatsoever of the National Dex.
Is the National Dex not a thing anymore?