I know what you mean, but you need to find a different or more nuanced term. Deduplication is abstraction, it just isn't an abstraction mapped to the domain problem. Even a compression algorithm abstracts:
An abstraction can be seen as a compression process, mapping multiple different pieces of constituent data to a single piece of abstract data; [1]
An abstraction can be seen as a compression process, mapping multiple different pieces of constituent data to a single piece of abstract data; [1]
There are wrong abstractions.
[1] https://en.wikipedia.org/wiki/Abstraction#Compression