Typo in one noise settings boolean: It says "bandlands" instead of "badlands"

Can confirm.

That isn't the name of a biome, it's a surface rule, which is called bandlands because it generates bands

It used to be called "badlands" in 1.17.1, however.

I don't think surface rules as a concept even existed in this form until 21w41a. But anyway, it seems like only badland biomes use the bandlands type, so maybe they're intended to have the same name

It's possible that the bandlands/badlands thing is an internal 'Easter egg'