As to todays demo scene, I guess it has to find an active interest for the works, have some relevance in todays world and find a route out into the world. Very much like the PD Houses. What could be useful is a publisher, possibly.
They didn't have publishers back then, so why would they need them now
'You can write a book, but I doubt you will publish it'
You don't need a publisher when you release something to be distributed for free, just like back in the days. Like I said, the PD houses plain ripped off the demo scene, and very, very few groups actually wanted the PD houses to sell their works.
(edit)A good comparison in modern days could be selling books made entirely out of wikipedia articles (which some companies actually do).