There have been a few studies on the systemic effects of wage transparency with respect to average pay. They tend to indicate, as in this paper [0] from 2021 for example, that wage transparency suppresses average wages over time. The proposed mechanisms for the wage suppressing effects seem eminently plausible. I haven't seen much evidence that it would increase average wages, either anecdotally or in studies.
[0] https://www.nber.org/system/files/working_papers/w28903/w289...