This may have been made as a joke at the time. It could very well also be the first FiM PMV ever made.
There’s also this, which proves that the term Bronies has been around since at least November December
Where my bronies at?
insertclichename 8 months ago
With an upload date of October 29th 2010 (two days before my arrival in the fanbase, fyi) and the description telling us of how there were only 3 episodes out so far, this is like looking right into our history book. I found this in my favorites right around the same time as one of Mr Yaridovich’s first pony vids (that is now taken down unfortunately.) and that Rainbow Dash sits in for God – Monty Python Parody. Along with the VERY GOOD Trouble is a Friend PMV.
Then Dr Foreigner (the man who first found Derpy Hooves) pointed THIS VIDEO OUT TO ME which is officially the ORIGINAL FiM PMV. Uploaded on October 14th 2010.
Take a good look kids, this is what it was like in the fandom’s infancy.