What is a whitelist user? I see it listed as a role for some people in the indexing report.
I think the whitelist users were people who worked on web-indexing in the very beginning when it was still in the test phase. (At least that was what we were told in an Indexing Chat thread, one of the many which no longer has permission to be seen.)
It looks like these persons were experienced indexers who had been given early access to the Web Indexing program.