Yes - and I have heard from people who have said they were alarmed that their young daughters (around kindergarten/grade 1) were starting to say things like "Pretty girls don't do math" after they started school.   Very persistent messaging was needed at home to counter that stuff as well as a chat with the teacher and principal of the school to communicate what was happening.

The point about meritocracy across genders becomes irrelevant if women are not in the game.  The teacher I had who made sure to bully incessantly was all about taking people out of the game.   He may well have done this to guys too -- I would bet he did --  but I would bet he did it more to females.   This isn't systemic, but it does happen.  

Some of the best teachers I had at school made were men who made NO difference between kids based on their gender.   They made it a point that ALL the kids in their class could do the work by the time they finished the school year.   They were the best.