Why would Cyric be represented by the symbols of the Dead Three and be referred to as both male and female?
I personally do not support this theory. But it can be justified. That is, the Cyric is a mad deity, and his domain is deception. It is possible that he tricked the goblins, drow and other followers into posing as both a woman and a man. The use of the symbols of the Dead Three can be justified by the fact that initially Cyric usurped their orbs when he killed Leira and making himself the God of Deception, Murder, Strife, the Dead. By the way, it seems strange to me that Cyric is not on the list of deities. Perhaps this is due to the fact that the game is in EA, but it's still weird.
We know that the Dead Three are generally behind the crisis going on in the Western Heartlands. From the press kit: "we find ourselves on the center stage of a complot hatched by none other than the Dead Three: the gods of Murder, Tyranny, and Death." I don't see how both the Dead Three and Cyric could fit in with this. Perhaps one or the other, but not both parties.
In addition, the divine hooded skeleton in the camp is very likely to be Jergal, due to the several dialogue options explored. Considering Jergal allowed Bane, Bhaal, and Myrkul to assume his power, it is possible he has been brought back to atone for his crime. Perhaps Ao, or lawful deity by the command of Ao, say Helm, is responsible for this, and has set the hooded skeleton on his divine mission. This would also explain why Jergal is hanging around the camp assisting the PCs.
Jergal was never gone, he's been working for Myrkul, then Cyric and now for Kelemvor as scribe of the dead recording everything that dies since he passed most of his power to the Three. I'm not sure why he would be punished now for it either, considering how long ago that happened.
Also, he's pretty busy recording things, so I doubt the skeleton is him. The skeleton could be working for Jergal thought.