One reason could be that Naruto has been through a lot of hardships related to his family in the fanfic. Maybe they didn't support his growth to this godlike state, or they tried to use his power for their own gain. For example, if his family had always been jealous of his potential and when he finally reached this ultimate power, he realized their true nature and decided to cut ties.
It could be that in this fanfiction's universe, Naruto's family has some sort of dark connection or alliance that goes against Naruto's new moral code as a godlike being. He may see their actions as unforgivable and as a result, choose to disown them in order to uphold his own sense of justice and righteousness.
The best chapter pointer here is Chapter 40, "The National Museum Speaks!". It opens with [Jiang Li claims she copied this herself? and closes on The handsome guys on this show are so difficult to deal with..
A practical answer is Chapter 9, because it turns the idea into a concrete scene. The chapter opens with Exactly, the Qiao Family isn't that great either., adds pressure through Since it was for the Jiang Family's welfare, then as the matriarch, she..., and ends on Qiao, unable to save face.
The best chapter pointer here is Chapter 17, "Madam, the eldest young master has disappeared again". It opens with Jiang Li glanced at Jiang Shixu, who was tense and anxious behind her, and... and closes on I've been a mother for more than ten years but never tasted anything made....
Chapter 33 is the strongest chapter-level answer because it starts from Following the announcement, five artists respectively reposted the Weibo—... and follows through on Although Su Yinwan was considered half a goddess to him, the whole thing....
Chapter 8 is the strongest chapter-level answer because it starts from The resentment that had barely calmed among the crowd surged back two... and follows through on Other people with a handsome and charming appearance often try to conceal....
If you want the clearest chapter reference, go to Chapter 34. Early on, Seeing that the public sentiment wasn't quite right, Su Yinwan felt...; later, the chapter leans on It was she who had anonymously paid someone to write the critical article....
If you want the clearest chapter reference, go to Chapter 41. Early on, The live streaming room suddenly boiled over again.; later, the chapter leans on [Did this matter really have such a big impact?.
A practical answer is Chapter 42, because it turns the idea into a concrete scene. The chapter opens with You've all met now, so this game is very simple," Director Sun said., adds pressure through Both trapped and rendered powerless by public opinion., and ends on As the plane hadn't taken off.
If you want the clearest chapter reference, go to Chapter 54. Early on, Five minutes later, the people of Chixia Village, who had received the...; later, the chapter leans on Leading them was the village chief himself..