Been away from Berlin for 7 months or so and I'm really saddened and surprised to hear that about KitKat. It's a complex line to navigate in there always but that's part of the beauty of it - I've had plenty of uncomfortable or challenging experiences in there but always felt fundamentally safe, and know many of my friends, especially women, find it a safe (but sometimes challenging) space. It really does depend on the whole culture participating in holding the line, and it sounds like it's faltering recently.

My experience of KitKat is that unwanted attention of any kind (which depending on the night might not be super rare) is quickly shut down by the people in the immediate area before the staff even get close, and then the staff respond very quickly to it, especially if someone who is a regular calls attention.