That's quite enlightening. My comment was due to my industry-related naiveté. I thought a principal PM has the final say on both the features and the business side of a product. I didn't realize VPs add additional filters.
Principal is a job level. It is above Senior. A single product frequently has multiple Product Managers, some of whom are Senior PMs, some are Principal PMs, and some are "just" PMs. You could even have a Senior Principal PM.
