You know, I read that previously several places, but when I mentioned that, I was told that no importing occurred. Later, I read that various content was manually entered, in the form of posts. I was told that this also didn't happen, or only on a limited basis. My understanding is that this forum started in 2008, but I haven't gotten anything firm on that, either. I was referred to the history page. However it happened, it's what we have, now.
Changing webhosts usually wouldn't affect content, if imported properly. The content on this forum is in MYSQL, which has workable import/export functionality. I understand that the forum software changed. THAT can affect the transition, because the tables and fields would be different. Someone would have to use a special import query. Sometimes, things happen. Usually, there are character set mismatches, or improper escaping of special characters, memory overflow errors, etc that cause issues.