why would i want to keep the duplicates when removing duplicates

Question

i used kutools to sort my inbox and not losing a single email is crucial to me, i have thousands of duplicates that were caused by an inport gone wrong back in 2016 so these duplicates have the date 2016 mostly, when using kutools i had these removed blindly thinking it's always going to keep the oldest, then i did a smaller search and it was defaulting to keeping the newer fake date emails, meaning i have to put everything back and redo the entire thing.

please tell me who would want to delete duplicates and keep the newest date of them? it's called duplicates meaning a duplicate of the original why would i use a duplicate search and keep the duplicates and remove the originals, it should be called remove original not remove duplicates

為什麼我要在刪除重複項時保留重複項