From the handful of things posted here to HN about the "developing issue", it looks like:
* Someone was invited to give a keynote; this was voted on at some point
* After the invitation was made and everything was done, some concerns were raised about the content of the talk -- apparently about whether the keynote slot would be seen as an endorsement of the technical contents by the Rust leadership.
* Someone in Rust leadership unilaterally asked for the talk to be downgraded from a keynote to a "normal talk", without telling anyone else or calling for another vote
* The invited speaker, recognizing something political going on, decided to "not play the game" and decided not to speak at all.
* One of the people who voted to invite said speaker to give a keynote, but never heard about the request to "downgrade", decided to resign.
As someone who is also involved in an open-source project with procedures and bylaws and such -- it seems like part of the issue has been certain people in the Rust leadership not being conscientious about following the process. I do believe that back-channel communication and coordination is necessary in real life. However, I also believe that confidence in the process itself is important. Having determined that something was necessary to be done, the person in question should have raised an official vote (perhaps talking to people individually beforehand); and having broken official procedures, that person should at very least apologize publicly for doing so, and perhaps be removed from a leadership role (at least for some period of time, maybe a year).
The author of this piece says people were "trying to do the right thing"; I mean, sure, we're all trying to do the right thing -- but when you screw up, you need to own it.