Jeez. Why even have a waitlist then. It would just give false hope to a bunch of people thinking that they have an outside chance. I would be curious to know the eventual acceptance rate of waitlisteds at various schools.
Boalt's waitlist is like what you say to a really nice guy who asks you out when you're already seeing someone. "I'm already seeing someone right now, but if I weren't, I'd go on a date with you." So you can let them know that they're cool, but you're unavailable.