This is the main issue I wanted to bring the conversation towards. instead I got flamed for making it seem like I am a "sue-aholic." Some people use their Github for business use and allowing Github to change a username without notice is bad blood. On top of that Github has no mention of telling its user base of changing usernames with or without notice. There is almost no mention that they can do whatever they like on their platform with your personal account details. If Github ever does end up changing someone's username and that person was doing what you said. Github would be in deeper trouble than what OP does have.

Obviously OP understands the company's decision for changing his username but he was allowed to have it in the beginning. It is odd to backtrack and force a name change without notice. Github should update their policy with new reasonings for allowing themselves the ability to change your username(or account details) without notice. Afterall If Github can change my username(or account details), I would like that to be communicated to me.