Well, here's the Bs As expert chiming in, so you can believe it.

Otherwise, we are left in the total vacuum of asking "how many waitlisted SWUs clear" without having a clue how many SWUs there are, how many are waitlisited, how many clear, or anything. But high season makes it somewhat less likely, slow season and higher C than J ratios make it more likely.

I've had perhaps one SWU not clear over the years, DFW-ZRH, and the return cleared only after a connecting pax failed to show up at the gate at ZRH. That's not especially relevant, however, because I often select flights after seeing if there is C availability using ExpertFlyer, and because ZRH is not EZE, among other reasons.