This annoying restriction is lifted in Nim 2; see the linked announcement.

Where in the announcement does it say that?

They likely read "overloadable enums" and went "Oh Rust calls their tagged unions enums" so assumed all languages did.

Oh, no, I actually misunderstood cobby's complaint: the field names, yes, those still have to be unique. Which is also a bit annoying, though I've seen discussions about changing it.