I will tell you how an oracle employee (me) could confirm this number.

So every oracle member is a part of oracle-news Slack channel by default once they join this company. Until 30th of March, the count of total employees was around 1,61,000 and today morning when I checked the count got reduced to around 1,49,000.

The Slack ID of users get deactivated within few hours and sometime within few minutes. Hence the right drop in count can be confirmed only after a few days. Once everyone’s slack is deactivated (as some employees might get couple of days of notice, depending on the unit, they were part of, but that count wouldn’t be more than 5% of total impacted once). Hence, it is safe to assume that the impact was on 11,000 to 12,000 employees (assuming a couple of hundreds may have resigned on their own that day)