Hi folks,
My suggestion to the Forums Council is a variation of #8: A new Discourse instance could replace UbuntuForums software (not a merge with Ubuntu Discourse).
Ubuntu needs this community: UbuntuForums fills a clear need for welcoming, threaded, conversation-based support. Neither IRC nor AskUbuntu can do that.
It's worth the effort to keep this community going: While UbuntuForums may be smaller than it was, the daily post count still indicates a healthy community.
The general Discourse platform does seem a good fit for many of the features currently on vBulletin, and the price is right. Canonical already operates at least two Discourse instances already. Another instance to replace UF does not seem too ambitious.
Why not merge? Ubuntu Discourse has a different mission than both UbuntuForums and AskUbuntu. The platforms serve different communities. As an Ubuntu Discourse moderator since 2017, my observation is that the user and developer communities have very different cultures of acceptable speech and behavior. Developers don't want to see every fire-and-forget rant, and confused users don't want to put on a tie to get a simple answer to a basic question. Therefore, I recommend that the communities continue to use separate platforms.
That's NOT a criticism of UbuntuForum moderation, which I have found over almost 20 years to be excellent: Fair, firm, and consistent. Don't change it. Frustrated and confused users feel welcome in UF and AU. As a primarily user-facing venue, that's appropriate and the welcoming culture is a great achievement. Ubuntu Discourse is a developer-facing venue, a workplace, and professional behavior is appropriately expected.
In theory, it might be possible to migrate a vBulletin database over to a Discourse instance. Or a static version can be added as a Discourse category, so the previous knowledge is not lost.
Discourse Privacy Concerns have been raised. Those are always important. The information stored ("collected") by a Discourse instance is the same as vBulletin -- Your username, email, and password. A Discourse instance is not a privacy hoover.
There will be a learning curve to any transition, and a maintenance burden. I suggest the Forums Council fire up a test instance and explore it for a month or two to see if it can meet their expectations, and perhaps to test a database migration.