Any Indian tribe or tribal organization may at any time submit a request to the Secretary for a determination that any law or regulation has been superseded by the Act and that the law has no applicability to any contract or proposed contract under the Act. The Secretary is required to provide an initial decision on such a request within 90 days after receipt. If such a request is denied, the Indian tribe or tribal organization may appeal under subpart L of these regulations. The Secretary shall provide notice of each determination made under this subpart to all Indian tribes and tribal organizations.