They retconned Dawn's story because... reasons. If its not the real Saint then he is a liability and should be kept under watch by the Vanguard at all times considering he just got mind controlled but apparently "Teh power of louve" is enough to snap him out of it... -blam!- can we get some actual interesting story telling? Anyway who am I kidding they'll find a way for him to cope with being a phony and turn into a "real boy". Can't believe they also wasted a CG cutscene on Saint going on about how he wants to go into the stars with Osiris and smooch each other till they die like we get it already. They also haven't had any meaningful interaction in the story other than how much they love each other and constantly going on about it since Lightfall.