Has a World Baseball Classic game ever ended 7-2?
Exactly once. On March 12, 2006, Cuba beat Venezuela 7-2, and no World Baseball Classic game before or since has ended that way. When it happened it was a scorigami, the first 7-2 in league history.
That makes 7-2 the 47th most common final score out of 80 that have ever occurred in World Baseball Classic. One point away, 8-2 has happened 1 times and 7-3 has happened 3 times.