[jedberg]

From Wikipedia: "Scholars have interpreted Cassius Dio's wording to indicate that the fire did not actually destroy the entire Library itself, but rather only a warehouse located near the docks being used by the Library to house scrolls"

If anything this would make the analogy even more apt, since only part of Yahoo is being destroyed. :)

Regardless, it's mostly used as a metaphor for the destruction of knowledge at this point.