For the Xbox One/Series X/Series S and for the PlayStation 4/5 there will be physical copies and digital copies. The details of the physical copies beyond that is scarce right now. I don't know how large the game is on consoles (meaning how many discs it will have). On the PC version on STEAM, the total hard drive space needed is 120 GB, I cannot find any information on Xbox or PlayStation's websites to determine size. If this is the same for consoles, then it will need 3 Dual layer Blu-ray discs to work on the Consoles. Either they will decrease the size on consoles, or they will use a Blu-ray XL or 4K Blu-ray disc for it.
As far as PC is concerned. I have not heard anything as to whether or not there will be a Physical copy. Judging by the size factor (120 GB) and the current market, I am guessing that a physical copy will not be available on the PC. Most computers nowadays are foregoing optical disc drives in order to leave more room for other components. Even when optical drives were still common on computers, most were not Blu-ray drives, but rather DVD drives. Yes, you still can purchase external Blu-ray drives for around $100 now, the amount of people who have those on PCs today is a lot less on Console, so it does not seem economically feasible for them to do physical copies for the PC.
Perhaps in the international market (where internet speeds are variable) there will be physical copies available, but in the US market, I just don't see it.