Do you mean just the a risk has been found when you were logged off, or all notifications? A legit notice should panic them. Unless I am the only one that thinks so, it is good for the end user to know that the email they just opened had a virus attached or that the site they went to just tried to install a virus, or that the link their friends sent them via facebook was really a virus. that way once it happens to them at work, they wont' go home and try to do the same thing.
They get a link from a friend via facebook, try to play it at work and nothing happens and nothing pops up, they assume that the company is just blocking stuff and then go home and try to run it. then they infect their home computer.
I myself left everything in enabled and will just check to see if anything was found overnight when any of the computers go on their few day glitch and popup the false message about the risk being found. I would rather deal with a few fake alerts for a few days than not have a person know when they have a legit virus found on their machine.