Absolutely. Raccoon has pretty tough teeth. If i am not mistaken, in the past, there is one member here whose chameleon's tail got severely injured from being attacked by raccoon during night time. The cage is pretty much broken into.
The man we purchase our parrots from said that one night he heard a bird screaming to he went outside.
He found a raccoon on the outside of a bird cage with its arms wrapped around the parrot inside. He was afraid to approach, but he got a baseball bat and smacked the shit out of the raccoon - I guess he tried to kill it, but it just took off running. The bird has puncture wounds and big tufts of feathers missing.
The next night he filled his trashcan with a buffet of the "poison meatballs".... goodbye raccoon.
Personally one of my parrots was attacked by a Rat during the night, but the parrot won and we found what was determined to be rat blood all over the cage and a trail leading to the side of the house. We think our bird got him in the neck and pinched the jugular.
Never leave your animals unchecked if you are in an area that is unsafe both people and wildlife wise. That mesh is easily broken by a Raptor bird or Raccoon, rats can gnaw through it, children could knock the whole thing over.
I would suggest purchasing a whole big set of thick wire fencing ( the ones that come in rolls and are a little less than 1/4 inch thick. Construct a wood frame using waterproofed wood and stainless steel joiners ( to prevent rust and wood decay from misting/rain). Wrap and use a staple gun to join the wire to the frame. Of course don't forget to create a door, so you and the cham can get in/out. I would even suggest wiring the floor, animals can dig.
furnish the cage so that a majority of the leaves/vines are in the center of the cage, and the cham has no reasons to climb the screen itself, or to hang around there. Use a suitable misting system with multiple nozzles. Find a place in your back yard where you can place the new cage, with about half exposed to sun, and half to shade. I would even suggest more to shade than to sun.
If done properly and safely, im sure your chameleons could have a very nice nice life living outside - but measures must be taken for safety and health.
S.F