It is very unlikely that I try to migrate the old forum posts into the new Tatoeba. First of all, there is no forum anymore in the new Tatoeba. Instead there is a "Comments" section, which lists the latest comments about the sentences.
I will set up a new forum someday, but probably not before a couple of months.
Most of the documentation is not relevant anymore in the new Tatoeba. I'll take the time to update it though. I will use this blog to store the new documentation articles.
In the new version, the sentences will be considered as added by unknown user at the date when the migration was done. There will be no more traces of the evolution of a sentence (modifications, suggestion of corrections, validation).
For a few thousands of sentences, I was able to retrieve the author and date when it was added, but that's all I could do. I suppose it is enough.
The statistics are based on the logs. Let's say in the previous version you had added 5 new sentences, and translated 7 sentences. In the new version, your stats will say that you have added 12 sentences, but there will be no indication on which ones you have translated. It will be considered as if you had added them as single sentences.