[quote=@IAmTheIsland]
Save for Lucian, couldn't we just keep the Princesses the same as in the game? Or do we want to base them loosely off of what worlds we go to?
[/quote]

Yeah, like in-canon Kairi remained a Princess of Heart so I can see Lucian remaining a Prince as well. The remaining Princesses can be from the worlds we decide to enter in Kingdom Hearts 3 since that's when they explain the Light passed onto a new generation.