So you're suggesting that people should shoot vertical video on the off-chance there might be an investigation where someone may prefer that format? Which you have zero evidence to back up that claim? Wow, that's dumb. REALLY dumb.
Here's an idea: why not just shoot video that doesn't make you look like a fucking moron?
As stated up above, most people default to vertical videos as that is how people regularly hold there phones. Plus, I doubt the person shooting this had the intention to upload it, they probably just wanted to show their friends.