As @anon89812132 pointed out, system updates only update the current system, they cannot create a new instance on its own.
If you did reboot into a new system, my guess is what completed it is that reboot, rather than the update.
Moving a system needs modifications in system configuration, most notably in the mounts. Those mounts being configured in files, they are not applied just by saving them. You also need to refresh the loaded state, either through a command that forces that part to take the updated configuration, or… by rebooting. If you started modifying those configuration, they may have been applied after that reboot.