it all depends there is licensing agreements both between GOG and the rights holders as well as if someone has the rights to certain versions elsewhere since GOG sells globally so if they say acquire the rights to sell Wizardry 1-5 by making a deal with the rights holder IPM/Gamepot in order to make them avalible in the states they will also have to work out a deal with series creator Andrew Greenburg due the settlement of a old lawsuit between him and Sirtech which affects any sales of those 5 Wizardry games here in the States but not elsewhere and in some cases devs make deals with third parties for releases in other regions and often times those deals grant them the rights to that release in that region so GOG will probley have to make a deal with them, what copies they actually can get access to as it's rare that the companies GOG has to go through actually still have the original masters or any copy of the games they have the rights too, and all that. So it's possible but it's not always as easy as people often make it out to be.
Again there are many variables to take into account so there is no real yes or no answer anyone can give unless we know all the details of GOG's deal with Disney, if Disney owns all the rights to certain versions of these games in all regions, are there obtainable copies in good enough quality pending the only available copies of that version are on floppy disk that GOG can take the data from, and so on.