GameStop vhs tapes

These are called store demo reels, and it wasn't just GameStop. Most major retailers that sell video games (Walmart, Target, Best Buy, etc.) all had these (and continue to have them digitally, like you said). These are occasionally uploaded to YouTube by people that either worked in the stores or for the video game companies, or by people who happen to acquire them secondhand.

There was once one on YouTube for Pokémon Red and Blue Versions (which I guess at this point would be considered "historic" due to the cultural significance of said games), but it was hit with a copyright strike before I was able to watch it (it was still visible as being in the uploader's playlist from Google). I contacted him shortly afterward and he said he could try and share it via alternative means, but life got in the way for him.

I also seem to remember seeing a store reel for Gold and Silver at Walmart in the months leading up to the North American launch (oddly enough, it was outside the electronics section, on a TV that they had mounted from the ceiling at various positions in the store). I'd be very interested to see more of these resurface.