Bandai: the physical copies of Dark Souls III will allow you to download the first game
Here in detail because we have been told by the Publisher:
" We are happy to give players multiple ways to purchase and enjoy their games and offer temporary promotions for those who purchase their own copy of a game. For this, all pre-order 1 day digital and physical copies of Dark Souls III for Xbox One will include a copy of the first Dark Souls. If you book in Digital Dark Souls III for Xbox One from the Xbox Store, you will receive a code for Dark Souls in 7-10 days. If you buy at launch a physical version of Dark Souls III for Xbox One from a retailer, a digital code for Dark Souls will be included in the game (at participating retailers and as long as stocks last). "
Please note that Dark Souls III is expected in stores and digital on 12 April.