Hey @tarica it still should! I was just trying to make the point that for the majority of use cases within Builder, it might be more reliable and straight forward to not rely on window load events 
That being said, it still should work in a custom code block, or within the JS window, I recommend checking out this article: Why is my custom code with script tags not loading on my Builder pages?
See if any of those recommendations help? Let me know!
But