Some varieties of apples blooms are frost sensitive. Others can shrug off a frost and not really care. It's a genetic difference in the cultivars.

https://www.degruyterbrill.com/document/doi/10.1515/biol-2025-1107/html

So if you see a big ass fan in the orchard, it's because the grower wanted to push a variety that is not well adapted to the local environment.