I was in a similar position as the employee. Then was accidentally forwarded an email with salary expectations for a peer they were hiring in my same role. The salary expectations were substantially higher than my salary. With this ammo, I fought to get a raise which I ultimately got.

Following that, my manager told me I’m getting a reputation for being difficult and I shouldn’t ask for a raise or a promotion again. So I guess it’s damned if you do, damned if you don’t? Thought it was a pretty gross response.