I'm confused--this goes against the current mantra that shutter speed must increase to compensate for high MP sensors.
You haven't read the thread; that "current mantra" is flat wrong.
You only have to increase shutter speed if you plan to start making bigger enlargements. If your enlargement size does not increase, your shutter speed does not have to increase.
Greater enlargement size requires a higher shutter speed regardless of resolution. For any camera, if you print to greater sizes, you will need a faster shutter speed. That's because printing larger increases the visible size of the blur.
People who are logic-challenged will enlarge a higher resolution image more than they did their lower resolution images, see more blur, and think that it's because of the higher resolution when it's really because of the higher enlargement.
They also don't realize that because the pixel size of their monitors is fixed, when they view a smaller camera sensor pixel at 100% of the monitor's pixel resolution, they're looking at a greater enlargement of the image than when they look at a larger camera sensor pixel at 100% of the monitor's pixel resolution. Greater image enlargement means greater visible motion blur--greater resolution has nothing to do with it and needs no "compensation" for anything.