How will the existing maps from CS:GO be updated in Counter-Strike 2?

There are 3 categories for maps coming to CS2. Touchstone maps are "basically perfect" and just get minor visual changes- like Dust 2. Other maps from CS: GO might end up in the "upgrades" category, where a stronger emphasis on visual reworking is involved. Then there's the "Overhauled" category, where Valve will make changes to maps from previous titles that may be quite significant to how those maps play.