Due to limited developer time and resources, the Whonix Project will end support for Qubes 3.2 on 2018-11-15.
Whonix support for Qubes OS
Please note that there is a distinction between Qubes supporting Whonix and Whonix supporting Qubes.
Qubes supporting Whonix means that Qubes OS allows the secure installation and use of Whonix TemplateVMs inside of Qubes OS. In this case, the Qubes developers work to ensure that code on the Qubes side is set up to accommodate Whonix TemplateVMs. (This is the same sense in which Qubes supports Fedora and Debian TemplateVMs.) Here is a table of the TemplateVM types that Qubes supports.
Whonix supporting Qubes means that Whonix is designed to be installable and usable as a pair of TemplateVMs inside of Qubes OS. In this case, the Whonix developers work to ensure that code on the Whonix side is set up to work inside of Qubes OS. (Similarly, the Whonix Project also works to ensure that Whonix can be installed inside of VirtualBox, for example.) Here is the Whonix version support policy for Qubes OS.
Both directions of support are necessary in order to ensure that Whonix functions properly inside of Qubes, and the Qubes and Whonix developers work together toward this shared goal.
This particular announcement concerns the second direction of support: Whonix supporting Qubes (in particular, ending support for Qubes 3.2).
Difference from EOL
Whonix 13 recently reached EOL (end-of-life) on 2018-09-30. When an OS or TemplateVM version reaches EOL, it no longer receives support from its maintainer. In this announcement, however, nothing is reaching EOL. Whonix is ending support for Qubes 3.2 2018-11-15, but the Qubes OS Project will continue to support Qubes 3.2 as planned until 2019-03-28.
What this means for you as a user
If you are using Qubes 4.0, this announcement does not affect you. If you are using Qubes 3.2, the Whonix Project will no longer support your system after 2018-11-15. This means that no developers from the Whonix Project will be monitoring or working on issues that pertain solely to Qubes 3.2. Therefore, the Whonix Project cannot guarantee that Whonix will continue to function as expected on Qubes 3.2.
However, since Qubes 3.2 is a mature platform, it is likely that Whonix will continue to work normally until Qubes 3.2 reaches EOL on 2019-03-28. Users who decide to continue using Whonix on Qubes 3.2 do so at their own risk. It is possible that an upgrade could break certain functionality, such as apt-get upgrading, networking, VM booting, or VM graphics. The Whonix Project believes it is unlikely (though not impossible) that a clearnet leak would result from continued use. For further assistance, please consult the Whonix support page.