Here's a quote from the Daylily World website:

We are saddened to announce the loss of our beloved co-founder, Mort Morss. Considering this loss and the limited assistance available, we have made the difficult decision to downsize our garden. Effective immediately, we will only have 2022 introductions and newer varieties available for purchase. But don’t worry! There is a possibility of another mass inventory reduction in the spring of 2026 (2021 and older Varieties).