Considering one collects 500k bits and uses the Request User Name Change (One Time).
Will the name change be renamed in all posts or the former name remains after the rename 
Best regards
Peasant.
Hello Peasant,
AFAIK, when you will change your name(By using bits or procedure) it will for sure change your name(Display Name + including all previous and new posts too). Only thing which I noticed is if you had used quotes while replying to people in your previous posts it will not change AFAIK (I have a habit of reading old posts(when very few new posts are there in forums), there I have seen an example). I apologies if I am wrong here, have seen an example in past so only thought to mention it here.
Thanks,
R. Singh