Technology previews are not intended for production use. After all, they're still in the early preview stage. They are in their infancy and are not fully baked. We are realists and recognize that some customers use them at their own risk. Technology previews are like taste tests at malls. We let people take a sip of Pepsi and a sip of Coke and tell us which one they like better. Regardless of which one they prefer, we are not promising to deliver a lifetime supply of soda. Sometimes people hate the taste of both!
We make technology previews available via Autodesk Labs so people can give us feedback. Most customers try them on test projects. If the technology preview works for them - great. If it does not work for them, no harm/no foul, since the customers are only playing with the technology on test projects. Since technology previews have an end date, customers try them on projects that end before the technology preview ends. Technology previews have a specific end date so no one confuses them with perpetual functionality that is associated with a product offering or subscription service. In fact, technology previews are offered for free to Subscription, non-Subscription, and educational users alike. When the previews end, I don't have a way to re-activate them. It's not part of the Labs process.
A technology is said to have graduated when the preview ends, and it is available somewhere else (e.g., Subscription Center, feature in a new product offering, new cloud-based service). A technology retires from Labs when the preview ends, and users can't get it anywhere. It may come back as another technology preview sometime later. It may show up in a future product offering. It is not necessarily dead, but in the meantime, customers can't get it. At the end of a technology preview, sometimes teams decide they need more feedback, so they conduct another technology preview.
Terminology is alive in the lab.