I doubt Naruto will be surprised and even if he is, it will be very minor detail.
They have a 10 tailed monster trying to kill them all, and Madara Uchiha also trying to kill them all.
They don't have time to be shocked, the most we will probably get is Naruto commenting on the situation and raising his eyebrows but that's it.
Plus the other Hokages will probably have his attention. Madara Uchiha might be a little curious, but I wouldn't get your hopes up for Naruto to be dumbstruck and staring in shock.
They have a 10 tailed monster trying to kill them all, and Madara Uchiha also trying to kill them all.
They don't have time to be shocked, the most we will probably get is Naruto commenting on the situation and raising his eyebrows but that's it.
Plus the other Hokages will probably have his attention. Madara Uchiha might be a little curious, but I wouldn't get your hopes up for Naruto to be dumbstruck and staring in shock.