My theory on Layla Hassan
Following the date of emails found in Layla computer, the modern day events of AC Origins occurred in October-November 2017. However, I think we are actually reliving Layla's genetic memories through the eyes of an unknown character of the future. At the end of the game, William Miles indicated that the Helicopter should take them in about an hour. Since this is not happen in The Hidden Ones, I think this genetic memories will continue in future games. I won't be surprise if the next game starts with Layla and William extraction, which will be an event from the pass at this point. From ACI (2007) to ACIII (2012), we were actually relieving the life of a future (2012) Desmond Miles. Perhaps they returned to such kind of formula.