Doesn't pollen also have to do with the "gender" of the trees? In gendered trees, male trees emit pollen and female trees intercept pollen.

Not all species of trees are gendered (dioecious) but various are. If reforestation used male trees at the expense of female, then pollen count will be higher.

Urban developers who made the mistake of using male trees, because they don't drop fruit/berries/seed pods, will make the residents suffer pollen.

Sugi and hinoki are apparently not gendered -- they're monoecious.