I just called the store and they said they don't know if he is actually 'signing'. It is called a discussion. The thing is, if his conversation with Matt Pinfield begins at 7, and lasts for 30 min, would he really have time to sign for very long if he intends to play at gramercy anytime before midnight?
I'd call again, you could've just gotten an employee who was used to the original info or just fed up with calls re: signings and such.
The website lists the Matt Pinfield interview with the space opening at 4pm. No waiting/lines, they will just open space @ 4 and then people with book & receipt get priority seating.
I called over the weekend cause I was scared that the listing didn't say "Signing" anymore as well, but without even asking outright about autographs the clerk informed me "Mr. Weiland will be signing copies of his book after the interview segment. It will be for folks who purchased the book & have B&N receipt as proof. He will not be signing any other merchandise, memorabilia, CDs, etc."
But regardless of the 2 different sayings from employees there, I would not show up at 7pm if I were you, that was merely the original scheduled event as signing only and even then I think it was just a default time until they figured out further details.