I am trying to make a 2024 version of my paladin. I can pick Oath of Devotion because it is free. I can pick the Xanathar’s options and Oathebreaker because they are from 2014 content I own, but I cannot pick the 2014 version of things I own if they’re in 2024 content I don’t own. I can’t use the Oath of the Ancients.
I know I can use 2014 subclasses with 2014 classes. I’m just wondering why they let me use some but not all of the 2014 subclasses I own with the 2024 classes. The Xanathar’s and DMG subclasses are 2014 content.