The museum's own internal request for clarification said they are administrative documents.

  ...According to the advice of February 7, 2019 issued by the Commission d'accès aux documents administratifs (CADA)1, engaged by you, the files in question would constitute communicable administrative documents, insofar as they are developed and held by the Rodin Museum as part of its public service mission. In addition, CADA rejected various arguments in favor of of their non-communicability2. It also indicates that these documents are reusable, including commercially, but that the museum can establish a pricing for the reuse of its three-dimensional scans.

Quoted from the 20190627 English version of the letter.