If they really wanted to do a mirror universe Borg, they should have done a true mirror version, like they only accept those who are willing to join and their purpose for assimilation is truly benevolent. Each "drone" is still an individual, they can leave the collective at their own free will, and their existing is to help understand and advance society.
Personally, I think they were just someone's way to get lines spoken as if from those alien comics (by Nathan Pyle) that are popular online right now.
Lines like, "Evasion is beneficial to us" instead of "Watch out". Or "Observe" instead of "Look".
I don't think there's any real story to it or, at least, no story that anyone at Cryptic cared to create before leaving/sleeping on the project.