Actually, I called the Avalon in Hollywood, and evidently they are getting a lot of calls. The woman who answered the phone knew why I was calling before I even finished a sentence.
She said that the concert was probably being booked through "Avalon Attractions", and not "Avalon Hollywood". (Avalon Hollywood is one of the venues that is managed by Avalon Attractions.) She said that since this is such a popular band, that the Avalon Hollywood is not a big enough venue.
Avalon Attractions manages over 50 different venues in the greater LA area. The most likely places would be the Palladium, which holds approx 3500 people and often hosts punk concerts, and the Home Depot center in Carson. They both have a large general admission section.