[MC-81834] "shade" tag does not work for item models

In custom resource packs, the "shade" tag does not work when used in an item model. This means that if a block is put on the head of the armor stand and rotated around it will change color quite drastically.
Example item model that attempts to use "shade": false:
{
    "textures": {
        "Black": "blocks/black",
        "Red": "blocks/red",
        "RedEdge": "blocks/red_edge",
        "White": "blocks/white",
        "WhiteEdge": "blocks/white_edge",
        "Green": "blocks/green",
        "GreenEdge": "blocks/green_edge"
    },
    "elements": [
        {
            "from": [16,12,16],
            "to": [31,27,31],
            "shade": false,
            "faces": {
                "up": {
                    "uv": [1,1,1,1],
                    "texture": "#Black"
                },
                "down": {
                    "uv": [1,1,1,1],
                    "texture": "#Black"
                },
                "west": {
                    "uv": [1,1,1,1],
                    "texture": "#Black"
                },
                "east": {
                    "uv": [1,1,1,1],
                    "texture": "#Black"
                },
                "north": {
                    "uv": [1,1,1,1],
                    "texture": "#Black"
                },
                "south": {
                    "uv": [1,1,1,1],
                    "texture": "#Black"
                }
            }
        },
        {
            "from": [16,12,32],
            "to": [30,26,31],
            "shade": false,
            "faces": {
                "up": {
                    "uv": [1,1,1,1],
                    "texture": "#Red"
                },
                "down": {
                    "uv": [1,1,1,1],
                    "texture": "#RedEdge"
                },
                "west": {
                    "uv": [1,1,1,1],
                    "texture": "#Red"
                },
                "east": {
                    "uv": [1,1,1,1],
                    "texture": "#Red"
                },
                "north": {
                    "uv": [1,1,1,1],
                    "texture": "#Red"
                }
            }
        },
        {
            "from": [31,12,16],
            "to": [32,26,30],
            "shade": false,
            "faces": {
                "up": {
                    "uv": [1,1,1,1],
                    "texture": "#WhiteEdge"
                },
                "down": {
                    "uv": [1,1,1,1],
                    "texture": "#White"
                },
                "east": {
                    "uv": [1,1,1,1],
                    "texture": "#White"
                },
                "north": {
                    "uv": [1,1,1,1],
                    "texture": "#White"
                },
                "south": {
                    "uv": [1,1,1,1],
                    "texture": "#White"
                }
            }
        },
        {
            "from": [16,27,16],
            "to": [30,28,30],
            "shade": false,
            "faces": {
                "up": {
                    "uv": [1,1,1,1],
                    "texture": "#Green"
                },
                "west": {
                    "uv": [1,1,1,1],
                    "texture": "#Green"
                },
                "east": {
                    "uv": [1,1,1,1],
                    "texture": "#Green"
                },
                "north": {
                    "uv": [1,1,1,1],
                    "texture": "#Green"
                },
                "south": {
                    "uv": [1,1,1,1],
                    "texture": "#Green"
                }
            }
        }
    ],
    "display": {
        "head": {
            "rotation": [ 0, 0, 0 ],
            "translation": [ 0, 0, 0 ],
            "scale": [ 1.603, 1.603, 1.603 ]
        },
        "gui": {
            "rotation": [ 0, 0, 0 ],
            "translation": [ 0, 1, -16 ],
            "scale": [ 1, 1, 1 ]
        }
    }
}