Boshin War fate sealed before it even started?

Following his resignation and the enthronement of Emperor Meiji, Tokugawa Yoshinobu was at Nijo Castle, in Kyoto. While he was there, a coup d'etat occurred, led by court noble Iwakura Tomomi, and backed by the armed force of Satsuma troops.

Per Mori Mayumi, Shogitai Ibun, pp. 83-84, Yoshinobu had 3,000 Aizu men and 1,500 Kuwana men, together with Shinsengumi and others, under his command, and to use Mori's words, "Yoshinobu missed his one chance to put down Satsuma by force." Yoshinobu chose instead to leave Kyoto, then some time later sent his armies back to Kyoto with his letter to the Emperor, and their progress was blocked outside Kyoto, which began the Battle of Toba-Fushimi and the Boshin War. Then a few days into the battle, he absconded with the lords of Aizu, Kuwana, Matsuyama, and others, leaving said armies without their seniormost leaders.

The reality remains though, that Yoshinobu let that chance while he was still in Kyoto slip him by. So I think that basically the fate of Toba-Fushimi and the war was sealed before either Toba-Fushimi or the Boshin war even started.

Worth thinking about.