Faction Change - Character Flagged for Rename

I have recently paid for a character transfer from Blackrock to Frostmourne as well as name change for the character Wubz. After the transfer completed I immediately faction changed to Horde without altering my character's name.
However after faction changing and specifying the correct name that I want, I am prompted to enter in a new name as the one I have chosen as been flagged for rename, and I am unable to choose the same name as it is "unavailable".
Is it possible for my character to keep its current name (Wubz) and remove the prompt flagging the name as invalid?