I remember seeing someone's project that was able to predict the physics path in Godot, I think on Twitter, but I don't remember exactly how they did it. I think what they did was: have an invisible copy of the ball/object, send it out into the physics world, track where it goes, and then using the tracked points of the invisible copy to draw a path. Using a dummy/invisible physics object that collides with the physics world (but does not modify it) is a common way to get the path like in the picture in most game engines.
If I find the project again, I will link it here.
