You're right, however after doing that, there will be quite a mess with user name in CGTRader, as it won't change completely - in some places new name will be shown, in others there will remain an old one. The only way to change it completely, is to delete your old account and to create new one, at least that's what i have been told by CGTrader staff a year ago. Practically not possible if one has some reputation worked out already...
I recently changed mine without having this issue, your username does stay the same as before, but your public profile name will change :)
