I’m sure we will inevitably reach a point where no one is releasing discs anymore. Every medium reaches a time where it is outmoded so this will go for all films, not just spaghettis.
But at the moment we are actually seeing more of these films getting mainstream releases than ever before. The upcoming Vengeance Trails box set is a perfect case in point. As was the Sartana one. None of these films had had a proper DVD release in the UK before and are now getting Bluray ones. And I know Arrow are planning more. So, in truth, although the day will inevitably come when discs will be outdated, right now we are in something of a golden age for disc releases I think.