If true, then I'm leaning towards your camp- 50,000 visitors/day might be reasonable long-term but you'd need to anticipate HUGE visitor numbers on day 0. Even 250,000 visitors/day is fewer than I'd expect from this site. I'd expect millions of tire-kickers on day 0. Truthfully, I was stunned by the quote - it came during an interview on MSNBC, obviously not an adversarial network.
Wasserman-Schultz is being ripped in the blogosphere right now. I'm not her biggest fan, but the attacks on her personally are a little unfair - she's (I'm assuming) being honest.