Sure, but there's a big difference in how a company sees the value. If you're talking about a property the company found success with, they surely want to hang onto the copyright and exclusive control of those assets with which to make sequels and the like, or even remasters and re-releases as Nintendo often does.

I particularly feel we need to clear up the copyright drama for abandoned works in particular, but there's a reasonable point that plenty of companies do continue to use and sell their game content for a very long time.

A failed project has very little value for the purposes of monetizing again later, you don't make a sequel to a game that you didn't make a profit on (usually). So it's a particularly good category to give away to the community.