How could they not be shocked!?
With those words, Minato Namikaze had truly acknowledged Amegakure's qualifications and status as the Sixth Great Ninja Village.
It was tantamount to indirectly acknowledging Uchiha Minato's identity and standing as Amegakure's Third Rain Shadow.
Of course, even without the great nations' recognition, Uchiha Minato was still the Third Rain Shadow, but that was not, after all, official recognition. It was not legitimate.
Now, however, Minato Namikaze's words amounted to official recognition of Uchiha Minato's identity and standing, of his very presence.
This was enormously beneficial to Uchiha Minato himself.
Sure enough, upon hearing Minato Namikaze's words, the Third Tsuchikage, Ōnoki, who harbored immense hatred for Amegakure, was the first to object, his eyes filled with icy coldness:
"Ever since the Shinobi World was established, there have only ever been Five Great Nations. When has there ever been any talk of six!? Iwagakure will be the first to object!"
As he spoke, Ōnoki looked toward the Kage of Kirigakure, Sunagakure, and the others, signaling them with his eyes.
Sensing Ōnoki's gaze, they all frowned.
Acknowledging Uchiha Minato's identity and standing would mean that the Shinobi World officially had a powerful, newly risen entity from now on. That was not something they wanted to see.
But if they refused to acknowledge him, and Konoha's Fourth Hokage, Minato Namikaze, took them to task over it, offending Konoha would not be a good thing either.
For a moment, both the Fourth Mizukage, Yagura, and Sunagakure's Fourth, Rasa, remained silent, neither stating a position.
As for Kumogakure's Fourth Raikage, A, who had once fought Uchiha Minato at close quarters, his eyes turned cold, and he slammed the table before him with a bang. "If the Land of Rain is to be admitted as the sixth great nation, and Amegakure