It's not really... the content from the E3 2019 and 2020 hands on demos is there.
There are no extra quests, there's some reference to future DLC, River Ward is still named Sobchak and was intended to be a primary character.
There's 6 primary characters Del, Ev, Johnny, Takemura, Panam and Sobchak (River) there are a few VOs of River that sound to me at least like a different voice actor and aren't accessible in the game files but.
All the game files are in the archive folder, same RAD Game Tools oodle compression as with previous CDPR games.
You can probably go through tweaksdb and look for anything marked [obsolete] but a lot of those things were just things that were clearly even more placeholders of what we got and are in the game right now, so that about as much as the references to the cut content goes.
You don't need to be a Dev to figure these things out really