There was a note in one of the older software updates that stated that changes in the speed dial numbers would not require a reboot when the change was made using the telephone keypad. Following this line of thinking, it may not be required when making the change from the web screens either. They may have opted to not rework the web screen to remove the reboot message, however most changes do require a reboot so it is best to go ahead and do it since it only takes a few seconds simply to avoid any problem later.
