Yes, I was aware of a bit of an issue with the time line and Fanny Alger. I wonder why apologists speculate that he held onto a revelation for some time period before sharing it? Did Joseph state that he received it before 1843 or is that just hopeful thinking on the part of apologists? Did he often wait before revealing revelations? Or was this an anomaly?
~edited~ I feel silly for not knowing this. Obviously my reading comprehension has plummeted lately. :(
You shouldn't feel silly for being confused about what statements Joseph Smith may have made about polygamy. The fact is he hardly spoke about it at all, aside from to make public denials. As far as I know, Joseph Smith never made any statement that would explain why he held back on sharing the revelation, or even if he really did receive it earlier than 1843. He never publicly acknowledged any of his polygamous relationships, and I don't recall any private acknowledgment of his "marriage" to Fanny. Both the idea of his being married to Fanny AND having received the revelation far earlier than 1843 are later constructs of apologists. At the time period, those who knew about Fanny viewed it as an affair. Joseph Smith just didn't talk about it at all.
Apologists speculate that he held back on because the people weren't "ready" for it that early. Of course, very few people were "ready" for it in 1843, since during Joseph Smith' lifetime, the idea of polygamy was only circulated among the leaders of the church, and not among the general population, many of whom had no idea that the church leaders were practicing polygamy at all. This is why the Nauvoo Expositor was such a big deal, it was going to blow the lid off the secret and
tell the general membership of the church. Joseph and the other leaders had been vigorously denying the practice or theory of polygamy, and didn't want it exposed. So Joseph ordered it destroyed, starting the chain of events that led to his death.