Have tried this on 3 different 6S+'s. Have always backed up my devices to iCloud and have never had an issue restoring to the same or new device. Now, when I do an iCloud restore, everything restores to my new phone except for iMessages. There is no setting to choose to back them up or not, it happens automatically as part of the backup. Anyone else with this issue? Edit: Backed up old device in iTunes and restored on new device and restore worked fine. Looks like there's an iCloud backup/redstore issue. Im going to attribute it to the new device release and retest an iCloud Backup/Restore in a few weeks.