I would try and steer my sons away from "girlie" toys but mainly because they are crap, rather than because they are made for girls. I think that if I had girls, I would also steer them away from a doll dressed in bright pink serving a 1970s style tea party. On the other hand, if I have offered them the choice and they choose a girls' toy, then they are welcom to it. When it comes to things like drinking cups, stacking toys or whatever, though, they get whatever is in front on the shelf, regardless of whether it is the the "boys'" or "girls'" version, the only difference being the colour.
All children are individuals but we all start from an idea of what a "typical" child is and then adapt if they are different. I can't see what is wrong with assuming one will have a typical boy, for instance, and then adapting if he is different from that. In the same way, I teach my sons that they will get married to a girl and have a family one day. Of course, as they get older, they will learn that there are exceptions to that rule and, if they show me they are one of them, I will adapt accordingly.
I must say that I have never seen a teacher trying to dissuade a girl or boy from playing with a toy because it is designed for the other sex. Of course, were that to happen, it would be wrong. On the other hand, observing, when out of the school setting, that boys are behaving like "typical boys" is not wrong at all.