Wubi was only "discontinued" by a very strange sense of that term, as it continues shipping on official Ubuntu ISOs and working.
Furthermore, even if we were to consider Wubi unsupported starting with 13.04, Ubuntu 12.04 LTS remains supported and won't be end-of-life for about 2.5 more years.
Now for the details...
Some background information on the current status of Wubi:
Wubi continues to ship with new versions of Ubuntu and to be maintained. 13.04 was apparently the only release that didn't have
wubi.exe on the official desktop ISO.
It's true that we're generally trying to discourage people from using Wubi on the new releases. There is also the issue that with a preinstalled Windows 8 system, Wubi won't work (though there are still many Windows users not falling in that category).
On other systems, Wubi still does work, even with the latest releases of Ubuntu. When run from the CD,
wubi.exe now acts to prompt the user to reboot and install Ubuntu in the usual way. When copied off of the CD, it continues to work.
Considering that it continues officially shipping with Ubuntu, I don't think it's necessarily accurate to say it's "discontinued" in the sense relevant to deciding what's end-of-life for our purposes.
I've just double checked this:
wubi.exe is present on the 14.04.1 CD (I checked
It is even on the Utopic daily-live images (I checked
utopic-desktop-amd64.iso from 20140830), foreshadowing its continued presence when 14.10 is released.
Anyway, the biggest problem with this proposal is that, even by the narrowest possible interpretation of the term, Wubi is officially supported for Ubuntu 12.04 LTS. While 12.10, 13.04, and 13.10 are end-of-life, 12.04 is an LTS release and remains supported through April 2017.
The presence of
wubi.exe on the latest 12.04 point release images wouldn't be a necessary condition to consider Wubi still supported for 12.04, because all the people who have installed Wubi systems are running supported releases and should be able to get help here through April 2017.
But it is there. I checked
ubuntu-12.04.5-desktop-amd64.iso. It contains
wubi.exe, as expected.
Since Wubi is still supported, at least on 12.04 (and we should likely consider it supported on later releases too), we shouldn't try to keep people from asking questions about it here. We shouldn't close questions for being about Wubi. And we certainly shouldn't remove or blacklist Wubi tags to create the impression that Wubi is unsupported or off-topic.
However, if Wubi were unsupported and off-topic, we would still not blacklist these tags. (You've tagged this meta question tag-blacklist-request so I presume this is part of what you're advocating.) Tag blacklisting is reserved for serious cases where a tag is doing considerable harm (or creating a huge heap of extra administrative work for the community). If Wubi were unsupported and off-topic, we'd want Wubi-related tags to continue existing for the same reason we have tags for some unofficial derivatives like mint:
- Some questions would be incidentally on-topic. We help people use Ubuntu to access files from (broken or not) Windows systems; presumably we'd help them use an Ubuntu live environment to access files from Wubi. At least some questions about migrating from Wubi to regular Ubuntu systems would be on-topic.
- We'd have a number of old questions about Wubi, many with valuable answers. There would be no good reason to delete them and destroy that information (more precisely: render it widely inaccessible). Those questions would still benefit from good tagging.
- For people who pay attention to our site's rules and scope, there would be a tag wiki explaining that most Wubi-related questions are off-topic.
- For people who don't pay attention to our site's rules and scope, there would be a Wubi tag we could monitor to efficiently identify posts for closure. (Not all new posts tagged that way would qualify for closure, but like with the mint tag, many would.)
That's all hypothetical at this point, though: many existing Wubi systems are not end-of-life and Wubi remains well within the scope of our site.