You are referring yourself to employees who have fears. One would imagine that if they fear reprisals then they will not lodge a complaint. It's difficult to take legal action in the absence of witnesses and evidence. That is why I'm very reticent to use number of complaints as an indicator.
These numbers indicate the number of institutions where 80% or more of francophone employees have stated that they are satisfied. That means that more than 20% of employees are dissatisfied, which is unacceptable. However, the advantage of these numbers is that they are based on an anonymous survey.