As of my knowledge cutoff in September 2021, there has never been a gap of 16 years between two consecutive FIFA World Cup tournaments. The FIFA World Cup is typically held every four years, with occasional adjustments made by FIFA, the international governing body for soccer, to accommodate scheduling conflicts or other considerations. The most notable disruptions in the World Cup schedule have occurred during times of global conflict, such as World War II, which led to the cancellation of the tournament in 1942 and 1946.
However, if there were to be a hypothetical 16-year gap between World Cup tournaments, it would likely be due to extraordinary circumstances, such as a major global crisis, political instability, or logistical challenges. These factors could potentially disrupt the regular schedule and necessitate a longer interval between tournaments. Nonetheless, such a prolonged gap has not occurred in the history of the FIFA World Cup thus far.