That is exactly the point of the ACLU suit. They seek to "establish" the wiccanism of Gardiner as legitimate. In essence to USE the 1st amendment to have government establish a religion.
That alone is enough to stop the game playing.
After a millenium or two they are free to reapply if they have established themselves like legitimate religion.
I think you are putting the cart before the horse here. Wicca has been a recognized religion for some time. There are even Wiccan chaplains in the armed forces. All that the ACLU is asking for here is that what's sauce for the goose be sauce for the gander.
If that's your fear, it's too late. Wicca has already been established as a religion. The US Army has Wiccan chaplains, Wiccan groups get the same legal and tax protections that Christian churches get, etc. In the eyes of the state, Wicca is already every bit as legitimate as Congregationalism, Catholicism, Islam and Judaism.
After a millenium or two they are free to reapply if they have established themselves like legitimate religion.
I'm sure our Mormon friends on this forum won't mind that you don't think they're a "legitimate religion" either.