I may have found that instead of dying sometime after the 1880 census, Albert Tally, may have done like his brother and reverted back to being a Blanchard like his mother. In 1900 I found an Albert Blanchard in St. Martin Parish. He was 28 [should have been 30]. I checked the 1880 census and did not find an Albert Blanchard who was 8. In 1910, I again found this same Albert Blanchard and he was 38 [should have been 40]. In 1920, the same Albert Blanchard was shown as being 50 which would have been the correct age [born in 1870]. I am not certain that it was your Albert, but there is a very good possibility that it was indeed him. He would have married about 1894. His wife was Erasie [not sure of spelling]. If possible you can find his marriage record in Father Hebert's books and you may find his father's name or at least his mother's name to confirm that this is the correct Albert who was the brother of your Joseph. This Albert lived in Breaux Bridge.
I was not able to find a definitive record of Joseph Blanchard's death, but it appears that he did die after 1910. Do you know the year of his death?
I'll let you know if I find anything else.