Unfortunately when migrating the sheer volume of information from one platform to another a certain amount will end up dropped. About the only way to have avoided this would have been to have completely shut the site down for several days while the migration was underway and then reopened with the new platform.
On another note, RoboOp just let me know that all new threads (at least for the time being) will go through an approval process.
Upside: trolls won't be able to post 200 threads in BDF in a short time frame when no Admin is logged in.
Downside: if no Admin is logged in it may take a while for a new thread to hit the public page.