Has a FIBA World Cup game ever ended 84-49?
Exactly once. On February 22, 2018, Brazil beat Colombia 84-49, and no FIBA World Cup game before or since has ended that way. When it happened it was a scorigami, the first 84-49 in league history.
That makes 84-49 the 475th most common final score out of 1,178 that have ever occurred in FIBA World Cup. One point away, 85-49 has happened never and 84-50 has happened 1 times.