Hats were always a connection to the stars. There were ancient priests in the Late Bronze Age that wore similar hats: 
From Berlin Gold Hat
The Witch hat could be connected to the Phrygian cap:
Hecate was often depicted wearing the Phrygian cap (one of her three aspects)
And then there’s the connection to the crown chakra. From the book A Handbook of Chakra Healing By Kalashatra Govinda:
The crown chakra connects humanity to the oneness of being. Here rests pure awareness untained by any duality: cosmic consciousness. The full unfolding of this chakra signifies the state known as enlightenment.
The crown chakra does not have a corresponding element, since its energy lies wholly outside of the material world. Its activation will open one’s perception of that which lies beyond the grasp of the senses. All religious and spiritual experiences are mediated by the crown chakra.