Indeed, but they will also stop selling or distributing them, meaning they will only be available via pirates/archivists (which are endlessly harassed by these companies).
These games will never stop being sold, they are too much of a reliable income stream. They will be discontinued in this form, and then rereleased in some new retro games pack or 'remastered' version or such like. It has happened several times before now and it will continue forever.