As a single data point, this is interesting: "GitHub's ElectronConf postponed because all the talks (selected through an unbiased, blind review process) were to be given by men."[0]

What's interesting, I suppose, is not that the selected speakers were all men (which could have happened by random chance), but the reaction by the conference organisers to that fact.

[0] https://old.reddit.com/r/javascript/comments/6f8u2s/githubs_...