A fun fact about "The Children," the unfinished sequel to TBK

"The Brothers Karamazov" was actually meant to be Dostoevsky's penultimate novel, though it has gone down in history as having been his magnum opus. At the time of his death in 1881, he was making preliminary notes for a sequel, believed to have been tentatively titled either "The Children" or "Atheism." In his foreword to TBK, Dostoevsky mentions that the TBK plot was meant to suffice as little more than a memoir of Alyosha, that the character may well appear undeveloped. In the sequel, Alyosha supposedly went on to incite a revolutionary movement, assassinated the Czar, and was tried and executed for the crime. This sequel was to take place 13 years after TBK. In TBK, Alyosha was 20, which would have made him 33 in the sequel and, presumably, 33 at the time of his death...and, incidentally, this is commonly held to be the age that Christ was during the crucifiction.

I am hugely interested by what you have posted since the novel never delivered on the promise of Alyosha being the hero of the novel (even though its a tremendous novel and probably the best I have ever written).

Where did you get this info? Is this definite? And is anything more known about this sequel and is there an good discussion about the Author's Note where he says Alyosha is the hero but the following novel doesn't bear it out?