Because if they include things to make it one whole “Saga” with explicit links to the PT and the SW Story films it’s unlikely they want any weird stray threads lying around. It’s always been a Special Edition. It’s always been one interconnected series. George Lucas was a genius and this was all part of his original vision. Solo and Rogue One were smooth productions. It’s all one nice brand friendly package and all remnants of the old versions will be swept away.