Kabuto said to madara he uses edo tensei better than those before him, he said Orochimaru prefected this jutsu, so I don't think the last chapter was what he meant by surpassing those before him because the jutsu's affect in the variation he did, more or less is the same. But what I think is gonna happen with some loop hole for the summoner to become a edo tensied summoning and become immortal more or less with the exceptions like death god summoning technique and hopefully some others in the future.
I think hes surpassing Orochimaru's version of immortality by being a edo tensied summoning.
But one who could argue is there such a thing as immortality? Even edo tensei can be dealt with the death god seal.