I don't think anything is excluded by default. If you look at the McAfee Default policy under your On-Access Default Processes policy, there is nothing in the exclusions.
Now, there are default processes excluded from the Access Protection Policies within the McAfee Default policy, but that is not for scanning.
In VSE 8.5 there was the option when adding exclusion to exclude "Files protected by Windows File Protection". In VSE this option went away because those file are excluded by default. My question is what are those files and their location?