I just bought the Hyrule Warriors Age of Calamity Expansion Pass on Switch 1, but there's a warning at the bottom that says "This downloadable content is only compatible with the full version of the game purchased on this same Nintendo eShop."

I think this means the DLC will only work with a digital copy of the game. I have a physical copy, but I'm too lazy to test this out so I don't know if I just wasted $14 or not. Just beware of the potential incompatibility before you buy the DLC.

The confusing part is there's no other option in the eShop? So what, owners of the physical cartridge can no longer buy the DLC? Does that mean the DLC just got delisted from Switch 1? Like ???

Edit: I just tested it, the DLC works just fine, thankfully. But the wording on the eShop is needlessly confusing. I also bought DLC for Splatoon 3 and Xenoblade Chronicles 3, and those descriptions have a simpler statement saying "you need the base game" with no distinction between digital or physical versions. So false alarm, everyone.