Bill, I really don't know the specifics of this situation in SpaceX, and I don't think you do, either.
Speaking from actual personal experience, individuals at the top of power structures almost always have subordinates who are the actual recipients of e-mails to those individuals, just as they have "secretaries" (if not armed guards) at their office doors to make sure nobody gets in "without an appointment".
Having personally been on the low-power end of some real public safety issues that were being handled improperly, I have some experience dealing with the "underlings" who block contacts. In my case, I did warn them that I would not stay silent and gave them a year to "come clean", which they did not do. So, I sent an e-mail to the top people, and did not make it "classified" so it was not withheld from the public. That was all that would kick the issue into the open - once public, it could no longer be ignored. I was not in a situation where I could easily be fired for doing that, but I was (illegally and counter-to-established-procedures) harassed in ways that were hard to trace back to whoever the instigators were.
So, I am not about to condemn others who use publicity to confront corporate suppression. Yes, the issues are much different, but the problem of corporate communication suppression is still relevant.