The journal guidelines clearly state the following:

Include persistent identifiers, such as a Digital Object Identifier (DOI), in references for datasets and program codes. Persistent identifiers ensure future access to unique published digital objects, such as a piece of text or datasets. Persistent identifiers are assigned to datasets by digital archives, such as institutional repositories and partners in the Data Preservation Alliance for the Social Sciences (Data-PASS).

Source

You might be comparing the papers with the style and see that the papers don't have the DOI, but often journals want you to include important identifiers like the DOI to improve their processes before typesetting a paper. Unless you have a concrete request from the publisher/journal to remove this, we would not change our style.