I prefer to be shaved because hair retains smell and I started to sweat excessively as I age. Much easier to stay fresh without hair there, same reason I shave my pits all year round. Also, I like when my husband is freshly shaved when I go down on him and I suspect the reverse is true too. In general, I think if you receive oral, it's inconsiderate to not, at least, trim (ymmv). Other than that, if you're young, fit, and your privates don't smell funky in the evening, I don't see a reason to do anything about the hair there.