Why do anything at all about it?
The message is informational. It's not telling you there is something broken, wrong, or needs fixing.
I agree, however, you can understand the dismay of the user who only sees 'AutoUpdate Failed' with no additional details, and concludes there is something, then calls their Tier 1 Support Desk in a panic as a result (folllowed by an email, then an email, then a ticket, which arrives in my lap to answer ).
More importantly, the root problem is that the customers are about to undergo an external audit, and really don't want anything that would draw the gaze of the auditors. They want to be able to demonstrate to the auditors that everything works as expected, and that 'Update Failed' message looks odd and needs special explanation. So, if I can fix it, I would like to.
So...any ideas anyone?