PROCESSING STATUS NOT UPDATED WHEN CHANGING ACTIVITY STATUS (Doc ID 1309301.1)

There is knowledge base on the subject topic and in the 'Solution' section, it was described as

"However, because of design considerations, we had decided NOT to automatically update the processing status on the activity level. This is why we have left the field "Processing Status" editable, so that the user can update it manually to Inactive. The processing status on the project level is not editable for the user, as this will be updated automatically."

Any idea what's preventing the processing status to be updated like Project Status?

Thanks,