Gorilla Glass, which has become a nearly indispensable component of fullscreen phones everywhere, is most likely to become available in a form that can protect flexible displays for phones. However, Corning has indicated that it may not be there by the time the first generation of these devices are ready for production.
https://www.notebookcheck.net/Corning-details-the-challenges-in-bringing-Gorilla-Glass-for-foldables-to-the-market.374791.0.html