The Disney Vault is Alive and Well

The “Disney Vault” is the term used by Walt Disney Studios Home Entertainment for its policy of putting home video releases of Walt Disney Animation Studios’s animated featureson moratorium. Each Disney film is available for purchase for a limited time, after which it is put “in the vault” and not made available in stores for several years until it is once again released. This also means digital copies are not available on Disney Movies Anywherewhen those movies are currently in the Disney Vault. However most titles in the Vault are available to buy online permanently
— https://en.wikipedia.org/wiki/Disney_Vault