Many people were confused about Xenoblade 2 Torna - The Golden Country (Physical Version) description after E3 2018. Today Nintendo officially confirmed it as a standalone project, which you can buy and play without owning [base] Xenoblade 2 game.
https://twitter.com/NintendoEurope/status/1026483089374101506
https://twitter.com/NintendoEurope/status/1026483089374101506