I don't know about Elder Scrolls Online, but in the case of Xbox One only for other games I installed and ran it first by disc and then did a digital license and it worked fine and started up from the HDD without a disc. PS4 will actually make you uninstall and reinstall the game in the opposite way so if you're currently installed by disc it would make you uninstall the disc version to install the digital version and vice versa. Since you're on Xbox One the best way I would suggest doing is either trying it and testing if you plan on keeping the digital license no matter what happens or contact Xbox support by live chat or phone and see if they can offer some sort of return guarantee after you explain to them the issue, they typically don't do things like that for digital purchases which means they are more or less permanent, but they might make an exception, some do some don't. Let me put it this way in simpler terms the game will boot up, as I have done it with other games before, but the subject on the account part of it is what has me concerned.