Kopia also means a copy in Polish and the author is Polish. The first paragraph in the software's Github page also confirms the Polish origin of the name: https://github.com/kopia/kopia/
Tangentially, as far as OSS names of Polish go, kopia is pretty tame. A popular deduplicating app is named czkawka (hiccup). Now that choice is just mean towards non-Polish speakers. :)
Oh my, this is a fantastic view of life - from the czkawka github page:
Czkawka is a Polish word which means hiccup.
I chose this name because I wanted to hear people speaking other languages pronounce it, so feel free to spell it the way you want.
This name is not as bad as it seems, because I was also thinking about using words like żółć, gżegżółka or żołądź
To be more precise it means "copy" in the noun sense, not the verb. It's a distinction that a lot of bad translations from English fail to make, like when X changed "tweet" to "post".
"Kopia" means "copy" in Swedish and probably more Nordic languages, too. Very hard to pronounce in English so it would be interesting to hear it said.