Lots of high schools teach BC inclusive of AB material, so going directly from precalculus to BC can be the norm or common at these high schools (unlike those where BC starts where AB ends).
Skipping precalculus depends on whether the high school’s math curriculum is designed to allow strong students from algebra 1 / geometry / algebra 2 (or equivalent integrated math courses) to be prepared for calculus. This may be the case at some high schools, but probably not most.