If no existing residents were displaced by creating this township, then there is no problem with its existance. People can certianly vote with their feet. If they wish to segregate themselves, based on religion, while I think it is a bad idea, they are free and able to do so.
Originally, the town was going to ban the sale of contraceptives at the local pharmacies. That was changed under the appropriate threat of legal action. If the town attempts to write into law religious doctrine, there will and should be legal action. And the town will lose.
And, of course, when town laws and covenants come into conflict with state laws and covenants the town will lose. When town laws and covenants come into conflict with federal laws and covenants, the town will lose.
All in all, it is a dumb idea. But, for people who have more money than brains, the world awaits dumb ideas.