If you’re talking about the migration from the legacy Usenet era forum to this monstrosity we’re currently using, then yeah - I think so. But that’s a good thing if you ask me, because there were some pretty damning evidence of that Usenet warlord who never saw a hill he didn’t want to die on. He re-spawned a lot. :)
EDIT: Wait! No! I just read up that they migrated to a new server. So yeah, the legacy posts prior to this forum remain lost. But I haven’t noticed that any of my posts in this new forum missing. I will keep looking because I memorize all my posts, and can easily spot when something is missing or censored.