I've been having posts, that I'd swear I made, disappear from this and other forums for a while now. While it doesn't explain all the missing ones, it explains today's....
Even so, there could have been a window between the last snapshot and the migration. I definitely noticed a number that didn't make it. But no matter; the earth still spins.
I'm going to go back and try to recreate my awesome posts. Some will be worse, none will be better. Wish me luck.