Ok, I'm going to reply as a victim of rape at the hands of three different men.
I know it's not all men. We all know it's "not all men". But by talking about it, you are not going to demonise, you're not going to belittle, you are going to try to do something to address the absolutely abhorrent levels of violence against women and girls globally. And why would you not want to do that?
It doesn't matter if your son would or would not harm a girl, it's about creating a culture where the lower level misogynistic acts and comments are unacceptable. There is a great campaign by some police forces called "you're right, that's wrong" all about men standing up to their peers on misogyny.
As for walking behind a woman? At late, in a lonely area? Yes absolutely cross the road.
When "me too" happened, a close male friend of mine asked me questions about this. "If I'm walking in an area at night and there's a woman ahead of me, should I cross the road?" I so appreciated his question. Frankly he's the least threatening man you could ever meet but the fact he'd thought about it touched me. That's the kind of guy I'd like to bring up (and I have a son). A man who thinks about their impact on others. Who considers the feelings of others. Who sees it as "manly" to care.
"to drill into a boy from a young age that walking behind a girl is inappropriate is just nonsense"
It is nonsense and it's a nonsense you've made up OP.
I'm sorry to say but this comment is frankly disgusting.
"we don't teach girls that if they wear certain clothing they are going to become a victim for example."
In no way does what a woman wear threaten someone else. Do you see the differentiation there? Do you see how insulting that is for me, as a victim to read? It frankly makes me very depressed for your moral compass.
"This course does the complete opposite for boys and I'm sorry they will resent society and women for it in the long-term."
It does nothing of the sort. It is about setting minimum standards of behaviour. I do agree with you op that there is a vacuum in terms of male role models in some men's lives. But that doesn't mean that courses like this should not exist nor that they will have a bad impact, in fact, the opposite. Your views though are likely to reinforce the impact of the online "manosphere" type influencers.
In any case, I do talk about this with my teen son. His view on those kinds of online influencers is he sees them as chancers and a bit sad. Making money off of idiots. If you think in some way that's "weak" of him to think that, well I strongly disagree.
Stuff like this is sorely needed. May you never have to find out yourself why.