Boruto: Two Blue Vortex has established a significant new arc focused on the Shinobi world, and the latest chapter of the manga has finally shed light on why Uzumaki Boruto continues to keep the truth about Kawaki’s prominent role hidden from everyone in the village.
Boruto: Two Blue Vortex has begun three years after the events of Boruto: Naruto Next Generations.
The first story arc concluded with a major event when Kawaki forced Eida to use her Omniscience ability to make everyone in the Hidden Leaf village believe that Kawaki is the biological son of Naruto, and that Boruto had killed the Hokage. This caused Boruto to become a fugitive for years, continuing to plunge him into a precarious situation with the remaining members of the village after that brief period of time.
The first part of Boruto: Two Blue Vortex takes time to detail the many changes in the Hidden Leaf village in the three years since Boruto was forced to leave the village, and Kawaki has become one of the most trusted figures in the village. However, as Boruto is returning to the village to help resolve the issues caused by the Shinobi, Kawaki starts to question why Boruto still hasn’t tried to speak the truth to anyone. Boruto believes that no matter what he says, it won’t create any significant difference.

Why does Boruto still keep Kawaki’s truth hidden?
In chapter 15 of Boruto: Two Blue Vortex, Boruto and Kawaki meet again in the Hidden Leaf village, and they have their first real conversation since the time skip. Kawaki does not attack Boruto immediately, allowing both of them to engage in a dialogue for the first time. Kawaki wants to know why Boruto is not speaking to others about his use of Eida’s powers. Boruto feels that there’s nothing beneficial in revealing the truth about the circumstances that have transpired. He simply doesn’t trust him.
Previously, it was established that Eida’s powers function more complexly than initially understood. Instead of operating like a simple mind-reading ability, Omniscience rewrites the memories of everyone to make them believe that Kawaki is Naruto’s biological son throughout this time.
Therefore, Boruto understands that talking to others wouldn’t have much effect. While some people might believe him, others would not. This would create unnecessary problems as he needs to focus on dealing with the Shinobi before any of this becomes too overwhelming. Thus, in Boruto’s eyes, as long as the Hidden Leaf village operates normally in this situation, he will remain calm about being labeled a rogue ninja.

Even if Boruto speaks the truth, it may not be understood
Omniscience is a power that is difficult to perceive at its level, as Boruto speaking the truth to others would still not lead to understanding. Because even when some are inclined to trust him, Eida’s strength continues to rewrite the memories of the village’s inhabitants. Previously, Shikamaru could piece together information and believe Boruto could be Naruto’s true son, but even he could not trust the very memories about Boruto.
As a result, to overcome Eida’s strong influence, those who hear the truth have to navigate their own thoughts and doubts. For some reason, Uchiha Sarada and Kakei Sumire are the only ones who can completely avoid Eida’s influence without any connection to Otsutsuki, unlike Boruto and Kawaki.
Everyone else might forget Boruto’s existence, which is why Naruto’s son is acting appropriately in this case, talking to others would only complicate matters further. With the ongoing issues stemming from the Shinobi outside at this time, the Hidden Leaf village needs to be more united than ever.