I personally feel it depends on the bird and whether it connects said name to the concept of "I". If so, I would prefer to keep the name, or if it were that bad, then I would only slightly change it, and maybe use a nickname as well. If the bird picks up on the nickname, then I wouldnt worry about dropping the name for the most part, but would use the original name as a back up if the need be. I dont believe that a birds name will remind it of its past troubles.. except.. if there is a word, or a name the bird was called while being abused, for example if the person yelled "monster!" Every time they swung at the bird, then that word is associated with somethimg negative and the bird will react with fear. If the bird is reacting with fear to a certain word, or name, then of course dont use or say it. Very dependanr upon each particular case imo, but for the majority I think keeping the same or very similar name is good as birds feel comfort in routine/what is common to them.