Man, I hate when shit get's retconned like this, especially after so many years have passed. New MC looks and acts extra retarded too.
Maybe there are legit reasons why this was done but if it's just because people disliked Nikki or whatever and you want to make her more likeable, I doubt it will work. People that dislike her will still continue to do so. She was perfectly fine before, she had flaws and in a moment of weakness tried to exploit her friend and regrets that, there's character there.