After splitting the moon apart, Kaguya Otsutsuki's appearance had not been within Soji's expectations.
Although Soji had not watched much of Boruto in his previous life, he had practically memorized Shippuden's story by heart.
Therefore, Soji knew that after being sealed for thousands of years by Six Paths-level Planetary Devastation, Kaguya Otsutsuki must have already died.
There was plenty of evidence to support this.
The most direct evidence was that from beginning to end, Black Zetsu had spoken of "reviving" his mother, never rescuing her.
Soji had even studied the various Naruto Shippuden databooks.
All of them indicated that during the Fourth Shinobi World War, Kaguya Otsutsuki had returned from the dead.
If that was the case, then Kaguya Otsutsuki clearly should not have remained at the very center of the moon.
Otherwise, during the Fourth Shinobi World War, would Kaguya Otsutsuki not have been reviving within Madara Uchiha while simultaneously remaining sealed inside the moon?
That was obviously a bug.
Therefore, the reasonable explanation was that Kaguya Otsutsuki, who had originally been sealed within the moon, had died long ago.
Likewise, after Toneri split the moon in two with a single sword strike in the original work, there had been no sign of Kaguya Otsutsuki within it, proving the point once more.
According to Soji's speculation, after the Sage of Six Paths and Otsutsuki Hamura sealed Kaguya Otsutsuki using Six Paths-level Planetary Devastation—
After an unknown number of years, Kaguya Otsutsuki's body had perished.
Perhaps only a fragment of her consciousness, or rather, her soul, had remained sealed at the moon's core.
Of course, for powerhouses above the Six Paths level, losing their physical bodies did not count as true death.
Their souls still retained their undying nature!
Later, when Black Zetsu, that activated "Karma," was triggered, Kaguya Otsutsuki's