With the recent release of Whonix 14 and subsequent announcement that Whonix 13 will reach EOL (end-of-life) on 2018-09-30, we have updated the Supported Versions page with a new section explaining the Whonix support policy. For your convenience, the content of that section, as it currently appears, is reproduced below. In the future, users are advised to consult the Supported Versions page for the current version of the policy.
Whonix is an advanced feature in Qubes OS. Those who wish to use it must stay reasonably close to the cutting edge by upgrading to new stable versions of Qubes OS and Whonix TemplateVMs within a month of their respective releases. To be precise:
One month after a new stable version of Qubes OS is released, Whonix TemplateVMs will no longer be supported on any older version of Qubes OS. This means that users who wish to continue using Whonix TemplateVMs on Qubes must always upgrade to the latest stable Qubes OS version within one month of its release.
One month after new stable versions of Whonix TemplateVMs are released, older versions of Whonix TemplateVMs will no longer be supported. This means that users who wish to continue using Whonix TemplateVMs on Qubes must always upgrade to the latest stable Whonix TemplateVM versions within one month of their release.
We aim to announce both types of events one month in advance in order to remind users to upgrade.