I'm not sure how successful Chris Benoit's ''Pegasus Kid'' gimmick would have been in the WWE. He could still have debuted in 2000, get a few wins here and there, but do you really think he would have still been a 4-time Intercontinental Champion, a 3-time United States Champion, a 4-time Tag Team Champion, a former World Heavyweight Champion and the 2004 Royal Rumble winner? I feel that the fact that WWE never mentioned Benoit as having the nickname of ''The Pegasus Kid'', actually helped his career. ''The Rabid Wolverine'' gimmick made him what he was and helped elevate his career to the next level.
Now, back to your question... I think that even if Benoit's name was ''The Pegasus Kid'', if you watched the news on Benoit's double murder-suicide, I'm sure that the news reporter what say his real name. So, I don't think that still having that nickname, would do anything to protect Benoit's accomplishments and change the fact that WWE completely erased him for history.