No one expects Cyberpunk 2077 to be a game with a small file size, as basically everything we've heard about it so far indicates that it is a huge-ass adventure. And to be able to be shipped on a physical format, it seems like an extra Blu-ray might be needed.
According to a leak showing the Polish Xbox box art, spotted on Neo-Gaf, it clearly says that Cyberpunk 2077 is shipped on two Blu-ray discs. Most likely, you won't have to change discs while playing as you just install everything and then have disc 1 in your tray while playing. It is also a sign that Cyberpunk 2077 won't be an SSD friendly game for PlayStation 5 and Xbox Series X, with both having limited available storage (625 gigabyte rumoured for Sony's console, and 802 gigabyte for Microsoft's).