everyone's triggers were being alerted

It is not an expression that I know. I'm not sure it is even an expression that exists, but I would guess it means that everybody was getting tense and ready for a fight or shoot-out. "trigger" may refer to the trigger of a gun.

The title of the video speaks for itself. The expression "to get triggered" had become an internet meme recently due to so-called social justice warriors and feminists who are know to go berserk discussing topics like gender equality, race equality and so on. Urban dictionary:
Triggered
Getting filled with hate after seeing, hearing or experiencing something you can't stand.

Wich

The part that I don't quite understand about this line is that the verb 'alert' takes 'triggers,' not 'everyone,' as its object.

If it's not part of an idiom, how could this be?

listeneverIf it's not part of an idiom, how could this be?

Normally, the object of "alert" is a person. The idea of "alerting a trigger" seems a bit odd to me, and I wonder whether the wording has been slightly mangled of fluffed. The paucity of Google hits seems to suggest that it is not a known idiom. Perhaps another verb, other than "alert", should have bee

Thanks.
One more thing to ask.

The title has the term "peasant", which I guess means "farmer".

If so, why not "Thanksgiving peasants"?

listeneverThe title has the term "peasant",

I don't see where "peasant" is mentioned? Could you be misreading "pageant"?

Yes, I need new glasses.