a large number of kids have sleep apnea- many due to tonsillitis obstructing airways- there are almost 1/4 million tonsillectomies done every year- with many of those cases having caused sleep apnea- it is also estimated that many cases go undiagnosed- (it’s not easy to know if you have sleep apnea or not- people go for years without knowing it- )
Nevertheless, age and obesity are still the two greatest risk factors for sleep apnea, by far. Not tonsillectomies.