Has a FIBA World Cup game ever ended 56-53?
Exactly once. On July 1, 2018, Tunisia beat Cameroon 56-53, and no FIBA World Cup game before or since has ended that way. When it happened it was a scorigami, the first 56-53 in league history.
That makes 56-53 the 475th most common final score out of 1,178 that have ever occurred in FIBA World Cup. One point away, 57-53 has happened never and 56-54 has happened never.