Under normal circumstances, you are not supposed to add dates an existing AAP that does not have dates, unless you are already modifying the name for other reasons. As you describe it, conflicting identities exist, but those identities are not in the NAF. I believe that, by the rules, you do not currently have justification to add the dates to this heading The proper procedure is to create new authority records for the _other_ identities which lack them.
However, if you do create new authority records for the other identities, and find that you have difficulty resolving the conflict with no 98069349, then you are justified in adding dates (and/or other qualifiers) to the existing record in order to resolve the conflict. To do that, you would modify the existing record, rather than create a new record to replace no 98069349.
This is my understanding of the policies. In particular, I am looking at slide 18 of Module 7 of the NACO training slides.
Cataloging and Metadata Librarian
Bear with me if people have asked this kind of question many times before. no 98069349 Nelson, James is a name representing one person (i.e. it’s not undifferentiated), the editor of The complete murder sampler. However, I found in OCLC that there are many works under this heading that are not by this person. I propose to change the heading to Nelson, James, $d 1902-1981. I believe this is the correct thing to do, because there so many works [manifestations?] listed under “Nelson, James”, should I instead create a new heading and ask for the old one to be cancelled?
Cataloger, Monographs and Electronic Resources
Associate Professor of Bibliography
University of Oklahoma
Co-owner, PERSNAME-L, the list about personal names in bibliographic and authority records