Batch editing of related records is not currently supported. We would love to hear more about your use case for batch editing. Also, please check out the Esri Ideas page on Esri Community here and upvote that idea. We check the ideas page often and incorporate ideas into development when possible.
Hi Kerri, one common application is damage assessment after a disaster. There are many use cases. WebApp Builder had a great capability for this, as for related records. I +1 voted in the referenced threads.
