that's weird. try a restart if it's not working and you recently upgraded to 8.1 do a reset and load the backup (if you have any back up done before the upgrade)
Yeah, I think it's weird too, but anyway I reset the phone and nothing. No names in contact list, no numbers nothing. Only history is there but only with numbers, no names attached.
Every update erases everything on the phone. If for some reason it does not complete the migration after the install restart, you'll have a fresh phone. Calm down. Restore from a backup. Jesus.