> What do you mean, unstable?
I mean, the lack of transparency and partial information makes the situation unstable. Employers enjoy an information advantage. Times that this information advantage are breached --- whether by people selectively sharing information, leaks, etc --- cause big disruptions to morale and big movements of people.
Partial information is known to distort markets and cause wide variability in outcomes (and to create less stable equilibria than markets with better information flow).