I just confirmed with the IAEA publishing committee that the Style Manual (guidelines) is currently being updated, and not scheduled for release yet. Details on the DOI implementation were released in an internal memo dated Feb 2024. In quotation marks below are relevant excerpts of the internal memo.

"5. To incorporate DOIs in citations, the IAEA style for references has changed. All cited material, both IAEA and external, that has a DOI, should include the DOI as part of the reference, e.g. INTERNATIONAL ATOMIC ENERGY AGENCY, Regulations for the Safe Transport of Radioactive Material, IAEA Safety Standards Series No. SSR-6 (Rev.1), IAEA, Vienna (2018), https://doi.org/10.61092/iaea.ur52-my9o

6. Technical Officers are requested to ensure that reference lists in manuscripts submitted to the Publications Committee for approval are in the correct format and include DOIs where available (except supplementary material to conference proceedings, where they are encouraged, but not required)."

Will this be sufficient?

Thank you for your quick action and fix! Most certainly - will update again when the updated Style Manual is published.