If you'd like to dive deeper into this specific part of the story, I can: Explain the between the baby and Shouyou. Summarize the time skip that occurs right after this. Detail the reactions of the Shinsengumi during the fallout.
The core of this episode is the heavy realization that while the "Great Evil" (Utsuro) is gone, the man they loved (Shouyou) is still tied to that cycle of immortality. Gintoki is forced to confront the idea that his journey isn't over just because the war ended. He isn't fighting for the world anymore; he is fighting for the soul of his teacher. The Departure Gintama.: Shirogane no Tamashii-hen 2 Episode 10
In a poignant turn, Gintoki realizes he cannot return to his "normal" life at Yorozuya while this loose end remains. He leaves Shinpachi and Kagura behind, not out of malice, but to protect the home they built together. Key Themes If you'd like to dive deeper into this