The source is “I have told you this, and others, before but you disliked it so you ignored it.” You even commented in the same thread.
Literal 10 years worth of history is the source.
There actually is. Because the entire reason why Lone Wolf is the default now’a’days is because back during Warlords, there was A LOT of pressure on Blizzard to making the talent viable in raids (since M+ didn’t exist yet).
The desire of having a petless hunter class and it being MM was extremely popular, which is why folks used Lone Wolf even prior to it being a good option for PvE was the most common talent choice back then. Even in high-end raiding, because folks just didn’t want a pet and deal with the AI. They wanted to to play MM, and not have a random pet running around the place.
Lone Wolf’s existence and buffs is the literal proof as to why MM was desired to be a petless specialization. So the way to determine this is to go back and look at logs, forum posts, guides, and more from Warlords of Draenor and look at the number of people using Lone Wolf - despite it not being numerically better.
Even back then, with as numbers-driven as we are as players, folks used it as the default when playing MM.