I think it may be something more complicated. Without a doubt the MC is more than what meets the eye. The dead mindflayer with the hobgoblin, the dreams, the ending lines of EA, etc hint at this. Shar is all about memory loss too. I get the feeling we will get shoehorned to being attached to shar. Maybe a new shadow creature created by shar or a new subterfuge avatar of shar with a tadpole. A new checkmate to destroy her enemies.
I hadn't considered that possible turn of events. Instead, my mind went even darker and spun me a 'what if Gale is actually evil and faking everything right now' scenario. If you romanced him, that would make his eventual reveal all the more gut-wrenching. Suffice it to say, the idea really creeped me out.