Somewhat interesting article, I normally find these sorts of things a bit tedious. I do think there are some contradictions in some of the points regarding the honouring of the 'manager's schedule', 'maker's schedule' (that phrase made me wince) and communication, and the (incorrect) belief that there's no such thing as over-communication.
Maybe it was hinted at in the article, but while someone's job title may be Product Manager, they'll most likely be working with engineers who know far more about the product - it's capabilities and limitations - far more than the PM. Don't take it personally if something gets shot down, or if something you didn't know about is inserted into the monthly plan.