To the people thinking that Alivia is in the cover, note the following from Tor's excerpt accompanying the cover release:

Here, Rand stands with Callandor on the rocks of Shayol Ghul, heading down into its depths to confront the Dark One even as the sun itself vanishes from the world. Two Aes Sedai follow the Dragon Reborn into the mouth of darkness, two women who have been with Rand since the very beginning.

Definitely Moiraine and Nynaeve if there was any real doubt.

I'm doubtful regarding the "fake seal" theory. From KoD:

“Ah, yes. The seals. Indeed, they must be found.” Moridin’s smile was almost complacent. “Only three remain, all in al’Thor’s possession. though I doubt he has them with him. They’re too susceptible to breaking, now. He will have hidden them. Direct your people to places he has been. Search them yourselves.”

Would Moridin lie to the other Forsaken if he knew that one of Rand's seals was a fake? Maybe, but I kind of doubt it. Moridin knows that Rand is going to break the seals from his Dark prophecy and that any attempt to stop him from doing so is futile. He just wants to rig the fulfillment of that prophecy to the Shadow's best interest. This makes sense because Book VI is when Herid Fel realizes the seals need to be removed, and Taim gives Rand the seal because Moridin knows that the seals will be removed by Rand. Moridin's end-game is most likely to let Rand remove the seals and then unleash whatever he's been building up because he knows it's coming.