It means some anti-virus programs can interfere with the downloading and installing of Windows Updates. If you are no longer seeing failed ones, perhaps you got an update or changed some setting to allow them to work, if that had been a problem.
Certain updates require reboots and the anti-virus can interfere with this process if it has a scanning capability during these times.
Many updates that show failed will be installed later, so they may all already be installed, or as Pat says, superseded by others.
I suppose the point is, if you continue to see failures in the installs, you may want to find out why.