For all intents and purposes the content of the memo was balanced, polite, and restricted to the Google audience. The adult reaction should have been to punish the leaker (which I believe should be an actual breach of the code of conduct) and organize internal debates to allow multiple viewpoints to confront.
Rallying with the hysterical mass and shutting down the minority voice is certainly not about supporting debates and free speech. It's about throwing red meat to the wolves so the company can quietly solve its all too real gender pay gap issues without making too much PR waves.