Can you support that claim? I couldn't find when CEO pay went public but it sounds very likely like one of those causes were correlation definitely doesn't imply causation.
To put another way - at work, if you knew how much every employee made at work, it would probably be helpful in salary negotiations. Dont see why it would be different for ceos
[1]https://en.m.wikipedia.org/wiki/Executive_compensation_in_th...
[2]https://www.degruyter.com/document/doi/10.2202/1535-167X.120...
Edit: adding an additional paper on the topic https://www.princeton.edu/~amas/papers/CEODisclosureMandate....
What I suspect the person was referring to is the change where compensation became more tied to equity valuation.
[1]: https://americansfortaxfairness.org/tax-fairness-briefing-bo...