Yeah for sure. You can still download it from Steam at the moment if you already have a license for it, and probably for quite some years, so thank God for that. But if it ever stops being available for download for some reason from Steam, the game won’t be able to be downloaded at all anymore. On GOG, as long as you kept a backup of your personal installer file, the game will always be installable forever as long as you don’t lose your backups and there isn’t some crazy post-apocalyptic event that takes away our technology.