Is there no physical version of 1.5+2.5 for Xbox? Xbox Store lists the full assortment of KH games, including 1.5+2.5, but Amazon and Walmart don't have any listings for physical copies :
Kingdom Hearts 3' Release Time PS4, Xbox One: Here's When Fans Can Play
Kingdom Hearts III 3 Deluxe Edition PS4 XBOX ONE Steelbook Case *EMPTY* KH3 USA [NO GAME] : Video Games - Amazon.com