One quote from the article stood out for me:
Your product manager shouldn't just tell developers what to build. Specifying features is of limited utility - and may even be counterproductive - if your team doesn't understand how those features benefit customers. The product manager should specify what to improve and the metrics by which your team can judge that a feature (and the implementation thereof) actually benefits customers.
If you don't understand what you're trying to improve, how do you know that your suggestion is an improvement?