Dude you forgot about when Kabuto released the edo tensei, Obito put the pot in after the technique was released. By all acounts this would mean the brothers just vanished and the pot and gourd only had the brothers chakra, therefore, this would either reduce the moment on Guy and Lee to simple one time comedy or the oversimplified means of Madara's defeat.
It is too hard to believe that Madara will just be defeated by being sealed up.
As for the extraction, nothing said it was the entirety of the nine tails chakra. Remember Obito was an imperfect host due to the missing poritions of Gyuki and subsitute by means of the brothers.
Basically by all this, we need to conclude that the pots override the release seal of the edo tensei, if the brothers did in fact vanish and only the chakra was there as saying again, Naruto is as good as dead. Sakura doesn't have the technique of revival, there are many reasons why sakura dying is a bad choice on kishis part and yes these impacts on story, NS and NH are tremendous.
What should this really mean? Its more evident that the brothers are still in the pot, Remember unlike anyone else, the brothers had the power infused into them as supplementing their own natural chakra, they are like naruto without the presence of kurama, basically the ideal jinchurki, all the power none of the tailed beast risks. The power infused onto them became their own, as it was in life. This means that if the edo tensei is still working on them, unconnected by Kabuto, they are still present in there with their power. Basically right now they are the same as when madara was in edo tensei after the release the pot and gourd severed the connection to obito, but they are just weaker than madara and only have to stick around for the heroes to take them for their energy.
Basically we need to think of the pot and gourd like a thing of batteries, they still have the power, just because they removed the power from obito didn't necessarily mean it was all taken, remember its the brothers supplying it, after these past chapters, it was just hanging around in there, they are edo tensei, this means no chakra limit, so whatever was collected wasn't necessarily removed for good. Madara has both Kurama and Gyuki and as far as things went, madaras most likely going to become perfect.
Again remember what I keep posting about the sage? Some time after their creation, the young tailed beasts were told that they were all still linked to one another despite being separate entities. Hagoromo also told them that would eventually become one again, yet not as they originally were, and that one shall appear at that time to show them what true power is.
isn't this situation of Naruto getting blocked the revival from Yin Kurama only to have another save drop literally out of the sky, doesn't this seem so overly suspicious and just placement for not only what the sage said to occur but also save naruto? If the sage stuff really is true, then yeah Yin Kurama would have to be taken by Madara only for the new save to be discovered.
Can anyone seriously tell me that they think that madara would be defeated simply by tricking him into saying his name, can you seriously expect that to occur? This guy has all the power, knowledge of the sage and his tools more than any, just imagine how anticlimactic it would be if he was not only beaten by such a simple task, but if even the pot itself was the key the whole time. Do people seriously expect this one tool to be the answer to everything? It could hold a tailed beast but the whole ten tails? If that was the case, WHY DIDN'T THE SA DEPLOY THIS THING EARILER! THEY COULD HAVE SOLVED EVERYTHING WITH IT! JUST TRICKING ENEMIES INTO SAYING THEIR NAMES! THIS WAR WOULD HAVE BEEN OVER SO LONG AGO IF THEY DID THAT!
The pots are not empty, they very much do contain the brothers or the energy at least to revive naruto. You know what I expect? The brothers are there, kishi makes them fodder to save naruto, minato or so takes the energy, bam naruto is revived. The brothers pissed at whats happening, they make the mistake of attacking madara, they get reduced to nothing so we finally see a true example of one in edo tensei actually killed.
Seriously things are likely to be this simple. I could always be wrong but things are just sticking out so much right now, what else could you call it on?