I did catch that video of the Brahma chickens a couple of days ago. After doing some research, I only found a couple of examples of how big those chickens get, and none of those showed a person standing next to them for scale. The video gives the impression that they might be up to 3 feet tall.
Update: I was right. The article on Wikipedia says they range from 1.7 to 3 feet tall. If this was the main source of chicken in the US for nearly 80 years, I’m sure many of us ME people would have heard of the breed before now.
The Brahma is a large breed of chicken developed in the United States from very large birds imported from the Chinese port of Shanghai. The Brahma was the principal meat breed in the US from the 1850s until about 1930. – Wikipedia
Title: Mandela Effect – Kanya West, Mutant Chickens and More!!! (YT link) Uploaded by Scarab Performance.