If the user configures the capture.mode with any option that doesn't include the full document, the ExtractNewDocumentSMT will not be able to emit any after state from the document. Previously, in this case, it would have consumed the patch field, but this field is no longer relevant with change streams. The SMT needs to be updated that if the after field is empty, we should consult the value and extract the data from updateDescription.updatedFields to mirror the old patch functionality.