Couldn't it work just as easily the other way? Especially with tech in such high demand.
Posting wages might make it easier for companies to offer higher than others in an attempt to attract talent, leading to competition in the market, and salary inflation.
Sure, it could; I was just describing one way that posted wages could lead to stagnation.
I suspect that different things will happen in different markets. It seems (to me) that software development may be unaffected, administrative workers might benefit, and unskilled workers may suffer.
Posting wages might make it easier for companies to offer higher than others in an attempt to attract talent, leading to competition in the market, and salary inflation.