To begin, God wouldn't change His mind as God is unchangeable. In fact, there are some things God is incapable of -- He cannot be both logical and illogical. He cannot NOT exist. And because He is all-perfect, He cannot change.
Mosaic law, things like wearing certain clothing and not eating certain foods, were given directly to the nation of Israel. But it wasn't strictly things like this -- it was a predecessor for the bearing of Christ, who fulfilled the New Covenant. We are still bound by divine law, but not Mosaic law.