I was the moderator for this Q&A and I had extended conversation with Brandon at other points during the convention, so I will comment here.
Here are the exchanges that got substantial audience responses (the "woo!" moments he refers to):
While there was an audience response, I don't believe it's the false herald question, because I knew, and he knew I knew, that he was wriggling so I tried pinning him down (I am the one who nailed his verb tense for clarification in the transcript). His reference is to a question in which his wriggling went unnoticed. I believe his wriggling is related to the two following question batches:
Several hours after the panel, I asked him which question was the wriggle question. He of course laughed and said he wouldn't answer, and which point I said: Me: OK, Let's talk about the Nightwatcher and he got that rust-eating look on his face that said he was caught and said "sure!"
I didn't record it, but here's the takeaway: 1) The Nightwatcher and Stormfather are parallel entities such that NW:Cultivation::SF:Honor 2) There is sort of a parallel for Odium, but the parallel is the various Unmade instead of a single entitiy; 3) They are parallel in that they are all Splinters; 4) The Unmade are voluntary Splinters, because Odium ("like almost all of the other Shards") voluntarily splintered part of it's power 5) The SF is different from the others because it's a Sliver.
Edit: My first question in this off-camera inquiry was "Does the Nightwatcher predate the Shattering?" and he RAFO'ed on the grounds that the Nightwatcher and the Stormfather are parallel (see 1 above) and whatever he reveals about the Nightwatcher by extension spoils OathBringer which will be heavy on Dalinar and Stormfather reveals. He then trapped himself when he later said they were all parallel Shard-splinters (and thereby post-date the Shattering).