I think I might have found @bartv 's most recent response to this situation in another thread:
I’m really hoping this is not the last word on the matter, because that is a lot of WEC content to have lost, especially as many of us financially supported the transition to help ensure all previous forum content was preserved.
As a programmer, I know there must be a solution which could bring those topics in, even if it’s to remap / relocate those missing posts under a “Weekend Challenge - Archived Content” subsection, which then should leave the current forum intact.
I’m also wondering if all the missing image attachments was possibly due to a miscalculation of actual data to be transferred to the new forum. I’m sure there are many gigabytes in question, and perhaps some kind of underestimation of that data is now considered too formidable to transfer?
Still, there has got to be a way to achieve full transfer and fulfill the promise our community supported.
So much of that art and imagery is what helped make BlenderArtists what it was, before this forum, and the newer forum would only be richer for preserving that vital content, I feel.
Thank you in advance to @bartv for any further consideration and efforts in resolving this issue.