The 'new' servers that were available from launch or a few months after are now open to 1.0 character transfers - the only three servers which you cannot transfer any existing character to at the moment are the three new servers added for the PS4 version - Zodiark, Shinryu and Jenova (you can only create a new character on these servers). It's unclear when these three servers will be opened up for transfers, but later in the year is my guess.