He's saying the photographer specifically stacked the frame to increase the interference of the satellites. The same basic technique can be used in either direction - astronomers already use it to remove the thousands of satellites and other causes of interference in the night sky.

https://www.youtube.com/watch?v=mgMZa6G-q34 - a basic example using it to remove ISO noise

Edit: Actually, you can even see some satellites in the shot when he sets the layers to 'lighten' that are totally gone when he finishes the stacking.

No. A single long exposure would only show maybe one or two of those satellites. That's numerous exposures stacked on top of each other, such that every satellite visible in any of them is in the final result. This is completely backwards from how photo stacking is meant to be done (it's meant to remove satellites not visible in all of them.)