OP, I have teenage girls and a boy so can see it from both sides. DS has ASD so I imagine I spend more time having to explain social things to him than a parent of the average teenage boy, but we talk about consent and respect when he does thoughtless things like leaning his elbow on his sister's shoulder or going in my handbag without asking, etc and I've told him about the law around harassment and what counts as assault, etc.
I've not seen any evidence that DS is harassing anyone, but I can see from his lack of awareness around personal space that he could potentially harass people without knowing it's wrong/illegal in the future if I don't help him to learn these things.
OP, since your son's behaviour appears to have become an issue for others, I suggest you work on helping him to see things from the girls' perspective, and helping him to see how his female contemporaries have a right to live their lives without being harassed.
My DS has always had an earful about gender inequality and the fact women couldn't own property, vote, etc until relatively recently, and I think having sisters (one of whom receives unsolicited dick pics and requests for nudes on SnapChat) helps him to see things from the girls' perspective.
I think teaching teen boys about the realities of living as a girl or woman in a world of everyday sexism and harassment is essential in helping boys to understand what's acceptable and in protecting girls.
In summary, parenting teenagers is hard!