Hello Marta,
In the documentation for the schema, we say the following for the Publisher property: "The name of the entity that holds, archives, publishes, prints, distributes, releases, issues, or produces the resource. This property will be used to formulate the citation, so consider the prominence of the role."
I think that this certainly leaves open the use case you describe, namely using the data repository in this position.
Please let us know if you have further questions.
Regards,
Joan Starr
Chair, DataCite Metadata Working Group