Yes.... But actually no. For these games, sure, they're committed to update the dosbox, but for more modern games there's nothing that can be done on GOG since if the binary breaks for windows lack of backwards compatibility, they're done because they don't have access to the code. This works for these games because they're being emulated, so they can maintain them by extracting the ROM and updating the emulator.
IMO what Valve is doing is leaps ahead, Proton can be used to maintain even broken binaries by providing compatibility with older versions of binaries from Windows. Not to mention the runtime library shipped with Steam for native titles.
It's always mind boggling to me how GOG does something which Steam is already doing (sometimes, like this, they do a worse job at it), yet they get all of the credit as if they're revolutionizing the way the industry works. Allowing people to download a game they bought, even if delisted, is the standard, and Proton is a much better preservation tool than whatever GOG is doing behind the stages, because it's open source and if Steam ever goes under it will continue to exist, whereas on GOG solution you depend on GOG for it to keep working.