Ouch !
Between the rock and a real hard place-
Look; there can be no doubt that these Forums have been and continue to be a vital part of what makes Ubuntu Ubuntu.
This fact is what we present to Canonical for "The ultimate fate of the Forums is in Canonical's hands". This Forum's existence benefits Canonical in more ways than direct revenue generation. The efforts of the community is largely what built Ubuntu into what it is today and this Forum fosters that effort. Here from the beginning!
So - what we see now is a need to upgrade software and the user base.
Consider the efforts to inplace upgrade the current Forum's server software as opposed to rolling out a whole new venue.
We know from past experience what pain and how difficult it is to upgrade - and there is less resources today than last;
Would it not be a better option then to roll new - take as much time as needed to slowly migrate over, and also slowly re-up our current user base ? A modern platform would go a long way in gaining new users. This option is of-course contingent on Canonical willing to foot the bill and assist in the migration - and that our present staff does not burn out !
Death should not be considered