The longer answer is that of course it can be done (was done with the last CT forum platform change and with Sideways forum when we changed platforms to Invision some years ago), but it I acknowledge it is a big job.
I'm disappointed that this effort apparently isn't going to be made and would urge that this is reconsidered. If not, I hope that the previous forum will remain web accessible and searchable as an archive in some form, so that it's content can still be found via search engine. If not, a huge amount technical information and club history will be lost and this approach will make me think very seriously about whether to bother with detailed build threads on here in the future.
Nick