Sunset products are older SRGs, STIGs, Checklists, or Tools (i.e., DISA Products) that MAY be relevant to the vendor products they address, but are no longer supported by DISA for various reasons. The most common reason for this lack of DISA support is that the vendor product is outdated, superseded by a newer vendor product, or may be vendor non-support.
The lack of DISA support means that there is no active maintenance of the DISA product thus no updates of the product will be published. Lack of DISAmaintenance means that any new vulnerability in the vendor's product WILL NOT be captured for mitigation thus the DISA product either is, or will quickly become, out of date. Since DISA is no longer maintaining a given product, a SME responsible for, and knowledgeable about, the product may not be available thus customer support questions will most likely not be answerable.