Iirc, the main character has amnesia going into 3 and has forgotten the events of 1 and 2 so it's almost more true to form to start blind with 3.The amnesia is in witcher 1, not 3. If you don't transfer a save file you even get a re-cap/choice at the beginning of 3 where Geralt gets asked on the choices he would have made in witcher 2.
Someone else should confirm that though.