That is fair, I didn't check when the author posted. The first link (for me) when googling fbclid is the reddit post in r/analytics I linked to, which doesn't

That is fair, I didn't check when the author posted. The first link (for me) when googling fbclid is the reddit post in r/analytics I linked to, which doesn't have a ton of info but gives more than what the author had. Though you're correct, it was posted after the author originally posted, and I can't fault him/her for not checking in again a few days later.