Below story is from the LA Times on how Sarkisian shut out everyone from his past in Calif, most notably John Featherstone who persuaded him to start playing football at El Camino JC. Featherstone recently passed away and never heard from Sarkisian. Perhaps this conduct is normal for people who have overcame alcoholism in a need to block the past, don't know. But it supports your opinion.
Marsden should know he is not alone. On Sarkisian’s breakneck journey back to the top at Texas, he shut out other key people from his past, including his coach and mentor at Torrance’s El Camino College, the now-deceased John Featherstone, and El Camino offensive coordinator, Gene Engle. These men were important enough to Sarkisian that he invited them to a USC spring practice in 2015 as an acknowledgment of the role they played in his development.
Later that fall, Feather and Engle called to tell him that they were praying for him, they loved him and would support him through anything. Like Marsden, they never heard from Sarkisian again.
“Other than God, who really knows what’s in the heart of a man?” Engle says. “So I can’t speak to what’s inside Steve. Both Feather and I were really hurt. It bothers me a lot.”
https://www.latimes.com/sports/usc/story/2021-09-02/to-recover-from-usc-fall-texas-coach-steve-sarkisian-shut-out-those-who-built-him