Has a World Baseball Classic game ever ended 11-10?
Exactly once. On March 11, 2017, Venezuela beat Italy 11-10, and no World Baseball Classic game before or since has ended that way. When it happened it was a scorigami, the first 11-10 in league history.
That makes 11-10 the 47th most common final score out of 80 that have ever occurred in World Baseball Classic. One point away, 12-10 has happened never and 11-11 has happened never.