It's partially accurate. It's long been known there is an algorithm that gives Pre check to some passengers that have not enrolled in it. Some of the things that are believed to influence the algorithm are age, ticket type, flying history, others on the reservation, personally I believe that background check history is included as well. My mother is 62 and gets Pre about 75% of her flights, she also works for a school district and gets a background check every year for it.
Companions certainly aren't any higher on the list than others. It's possible that a companion would be given Pre, but not a given.