I recently mounted a 65" Sony on a Mantel Mount to a real brick fireplace built in the 80s. I used 4 redhead expansion bolts in the brick. I was only a little concerned. It has been there over a year and I have been back several times. It has even been through a minor earthquake. Still solid as a brick $4!+house. Pun intended.
I have mounted TVs to literally every surface you can imagine. Using dozens of different methods. All I know is that they are all still hanging. More than 1 way to skin a cat. No right or wrong as long as nothing comes crashing down.
"When I eat, it is the food that is scared." - Ron Swanson