I tried this out last night. It seems Xbox Live remembered I had the Klassic Sub-Zero and Ermac skins, as well as the Kombat Pass. Since I have the Klassic Skin Pack and the Kombat Pass was abolished long ago, non of those downloads were required.
Since I had the Kombat Pack, all the DLC characters, as well as the Compatibility Packs were present, but like the rest of you, no progress carried over, so no Quan Chi or Cyber Sub-Zero.
I will say, the game does not upscale well to 4K, but it certainly handles better on a base Xbox One controller over the Xbox 360 Controller!