To me the biggest insight here is that no matter what data science you're trying to do on a group of employees, the people you already have decided should be fired or promoted from that group are outliers and should be removed from the sample.

There are certainly times that you would want them included, but those can be classified under "budgeting," not gaining insight on a workforce.

Doesn’t the inclusion or exclusion of these people heavily depend on what type of insight you’re trying to get out of the data?