You are correct. You can even get a thru axle from Wolftooth Components and then get their trainer adapter. Think it works with any trainer. You just install the trainer caps and remove just the caps when you want to go outside.
https://www.wolftoothcomponents.com/collections/hub-related/products/wolf-axle-for-12mm-rear-thru-axle
https://www.wolftoothcomponents.com/collections/hub-related/products/wolf-axle-12mm-rear-thru-axle-trainer-cap
https://www.wolftoothcomponents.com/collections/hub-related/products/wolf-axle-for-12mm-rear-thru-axle
https://www.wolftoothcomponents.com/collections/hub-related/products/wolf-axle-12mm-rear-thru-axle-trainer-cap