It’s almost not necessary. Windows has – in contrast to Linux – a very good and long compatibility guarantee. You can put up any program from 1995 (at least being 32-bit) and it will start and run.
The things GOG is improving are some bugs that occur mostly in games, e.g. something with color palettes in pre-2002 games. But I think every game using DirectX 9 or later will work without any adaptations, even ten years from now.
The things GOG is improving are some bugs that occur mostly in games, e.g. something with color palettes in pre-2002 games. But I think every game using DirectX 9 or later will work without any adaptations, even ten years from now.