The Gakidō negates the properties of a Jutsu, meaning that the Bijūdama would in fact, not explode. An example of this ability is when the Gakidō absorbed Naruto's Fūton Rasenshuriken, and it didn't expand [You must be registered for see images
Sure they do.
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], which usually is an attribute of the technique. [
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] This being the case, the Bijūdama wouldn't explode, and would rather just wither down. Nagato's downfall against Naruto however, would be the time it takes for the Gakidō to absorb an attack, meaning that it'd have trouble with attacks like the Renzoku Bijūdama, since it would take too much time to absorb, and would provide an opening for other attacks, such as Taijutsu.The Yata no Kagami has been canonically stated to be invincible. If you disagree with Kishi's statement, take it up with him, I won't waste time explaining why it would be able to hold against the Bijūdama.
Not to mention that the scan you provided was of the blast created by seven Bijū at once.