Brandon, 22, made headlines earlier this year for feuding with dad Tommy, 56. The father/son relationship has been on rocky terms stemming back to an alleged physical altercation between the two that left the rocker with a bloody lip in March.
In an exclusive statement to PEOPLE at the time, Brandon claimed Tommy is battling alcoholism and that he had worked “tirelessly organizing an intervention.” (Tommy denied the allegations.)
“I wanted my dad’s hopeful sobriety and recovery to be a private family matter but, as a result of his accusations on social media, I feel forced to speak out,” he said. “I have and will continue to cooperate with law enforcement as needed. I love my father and just want to see him sober, happy and healthy.”
“I thank my Dad for paying for my treatment. It’s the best thing he’s ever done for me,” he wrote in a since-deleted Instagram post. “Today I am almost two years sober. Every day that goes by I feel ever more grateful. My clear mind has allowed me to do a lot with this time. So much so that I would like to offer to pay for his treatment.”
Page Six was the first to report Brandon’s casting.
The Hills: New Beginnings was announced in August, when a handful of cast members reunited on the red carpet at the MTV Video Music Awards. The revival, set to premiere in 2019, will reunite original cast members, alongside their children, friends and some new faces, and follow their personal and professional lives while living in Los Angeles.
“But she wants everyone to enjoy themselves,” the source added. “She wishes everyone the best.”
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As for Cavallari, 31? An insider told PEOPLE at least one reason for her absence is that the reboot would conflict with her current contract at E!, which recently announced a second season of Very Cavallari, a reality show following her life with husband Jay Cutler in Nashville as she manages her brand, Uncommon James.
“She can’t do the show because she has a contract with E!” the source said. “But she’s still close with Heidi and Spencer and is excited for them.”
The Hills: New Beginnings is slated to premiere in 2019.