It shows one of my friend's username VladBas02 when double checking before commencing Migration and when I go a few steps back to check Mojang profile info it clearly states my username correctly with it being Maarciel64. I have no idea how that's possible but I don't want to be stuck with a wrong name, specially because his profile is also legitimately bought and played on, with a different skin, server player history etc... 
Heres how it looks: