Pine pollen has a bit of weight (unlike some other types) and usually collects mainly on horizontal surfaces. Painting the siding should not be a problem, in fact painters in this area do not wait on it, however, like any dust it should not be painted over. Horizontal surfaces need to be dusted off well before painting. Acrylic paints dry fast enough to prevent the pollen from infiltrating the paint film to a degree that would cause paint failure.
A thorough power washing prior to any exterior paint job is highly recommended.
At almost any given time in spring, summer or fall we are painting over pollen that we cannot see.