Is it ethical to terminate employees who provided honest, albeit negative, feedback in a company survey?

There’s a case involving a company that conducted ‘anonymous’ feedback surveys, only to later let go of employees who reported high levels of stress or provided unfavorable evaluations. Was this an appropriate response? Shouldn’t management have viewed this as a chance to reassess their policies and work processes to create a better environment for their employees? Moreover, why claim that the surveys are anonymous if they’re not truly confidential?

I’d love to hear your opinions on this matter!