a.k.a. sunsetted, sunsetting
To "sunset" something means you are phasing it out or discontinuing it.
This term can be used in reference to brands and partnerships, or hardware and software products. Sunsetting something may be part of the original plan, however products and services are often sunsetted when they are no longer sufficiently profitable or when a company decides to change its focus.
Software vendors usually sunset older versions of their products when one or more newer version is available. In that context, sunsetting usually means that the product is no longer supported. For example, "we need to sunset that pronsumer blog we started last year."
Historical perspective: Microsoft sunset Internet Explorer 8 in 2014 because it was the last Internet browser for use with Windows XP, an older version operating system. If anyone is still running Windows XP, you will first need to upgrade Windows before upgrading Internet Explorer.
NetLingo Classification: Online Jargon