Yes Reback it can if you set it up to do that.

However, being more careful... it is better to manually download and test on a system or two before deploying automatically to all your systems. If Symantec were to push out a bad def (Heaven forbid) it may be possible to bring your entire organization to a screeching halt within minutes. ie. what if it were some kind of dat that was locking up network connectivity... you would have to VISIT every desktop and server to go repair it. Could your support team handle that kind of an issue? i.e. it has the potential of being more dangerous then a real virus. Testing a few in advance with a reboot as well should hopefully prevent something like that from happening to all your systems at once.