Honestly, it doesn't matter what the State Department thinks as the IC has said repeatedly that it was their information and that it was always classified. According to the law, only an interagency board has the power to override the IC's ruling, not the State Department.
The proper way to dispute classification:
Sec. 1.8. Classification Challenges. (a) Authorized holders of information who, in good faith, believe that its classification status is improper are encouraged and expected to challenge the classification status of the information in accordance with agency procedures established under paragraph (b) of this section.
(b) In accordance with implementing directives issued pursuant to this order, an agency head or senior agency official shall establish procedures under which authorized holders of information, including authorized holders outside the classifying agency, are encouraged and expected to challenge the classification of information that they believe is improperly classified or unclassified. These procedures shall ensure that:
(1) individuals are not subject to retribution for bringing such actions;
(2) an opportunity is provided for review by an impartial official or panel; and
(3) individuals are advised of their right to appeal agency decisions to the Interagency Security Classification Appeals Panel (Panel) established by section 5.3 of this order.
...
Sec. 5.3. Interagency Security Classification Appeals Panel.
(a) Establishment and administration.
(1) There is established an Interagency Security Classification Appeals Panel. The Departments of State, Defense, and Justice, the National Archives, the Office of the Director of National Intelligence, and the National Security Advisor shall each be represented by a senior-level representative who is a full-time or permanent part-time Federal officer or employee designated to serve as a member of the Panel by the respective agency head. The President shall designate a Chair from among the members of the Panel.
...
(b) Functions. The Panel shall:
(1) decide on appeals by persons who have filed classification challenges under section 1.8 of this order
...
(c) Rules and procedures. The Panel shall issue bylaws, which shall be published in the Federal Register. The bylaws shall establish the rules and procedures that the Panel will follow in accepting, considering, and issuing decisions on appeals.
32 CFR Part 2001 (the bylaws mentioned in (c)):
Article VI. First Function: Appeals of Agency Decisions Regarding Classification Challenges
F. Resolution of Appeals. The ISCAP may vote to affirm the agency's decision, to reverse the agency's decision in whole or in part, or to remand the matter to the agency for further consideration. A decision to reverse an agency's decision requires the affirmative vote of at least a majority of the members present.
I. Protection of Classified Information. All persons involved in the appeal shall make every effort to minimize the inclusion of classified information in the appeal file. Any classified information contained in the appeal file shall be handled and protected in accordance with the Order and its implementing directives. Information being challenged for classification shall remain classified unless and until a final decision is made to declassify it. In no instance will the ISCAP declassify properly classified information solely because of an agency's failure to prescribe or follow appropriate procedures for handling classification challenges.
(emphasis added)