So disappointing. The openness to crazy demos and experiments was part of the appeal. It feels we are going backwards.
There is no less openness, but the old experiences simply won't work with the new drivers and Oculus Home, which is important. The changes to the drivers since the last DK2 versions are extensive.
Many of the demos you've seen were just that, and never intended to be followed up on. Some developers disappeared, and others moved on to other projects (including for the CV1). At least one of the more famous demo guys was hired by Oculus to work on similar launch software (the cinema app, AFAIK).
It all boils down to the drivers in the end. There were major revisions to how VR is handled, both on the software and hardware fronts. The DK1 and DK2 mostly had apps that relied on you being able to extend your desktop to the Rift, which is no longer possible. This is a good thing, trust me. These apps had no knowledge about the sensor in the Oculus Rift, the one that detects whether or not you're wearing it right now and pauses the game if you take it off. They had no knowledge about the ability to go directly into Oculus Home. Many wrote their own routines for chromatic aberration and IPD, and included fixes for issues that no longer exist in the final Rift. There's a bunch of stuff like this. Devs who had existing software they wished to take into Oculus Home had to write major revisions to their software to do so, but Oculus provided these devs with a stopgap SDK during the last few months before release so everything would be ready.
You want those old experiences to get updated for the final Rift? Send the developers a message and see if they are still interested. It's all up to them, not Oculus.