As stated in the title, the linked status of every step in draft workflow cannot be edited. If you make a copy of an 'Active' state workflow, you will be able to edit the linked status. I believe that both creating a copy of a workflow and making a draft workflow should have the same ability in editing the linked status of a step.

Steps to reproduce

1. Create a workflow and activate it by associating with a workflow scheme and then to a project.
2. Create draft for the 'Active' state workflow
3. Click on the Steps under the newly created draft workflow
4. Click on any Step Name
5. Then, click on Edit step

See the image attachments for clarification.

Expected behaviour

The Linked Status should be editable in Draft Mode.

Actual behaviour

The Linked Status to the Step Name is uneditable (blurred out). In addition to that, underneath the Linked Status option, you will be seeing the following description:

Cannot change the linked status of an existing workflow step. 

Workaround

1. Go to JIRA administration > issues > workflow
2. Make a copy of the workflow that you need to edit
3. Once you have made a copy now the workflow will be present in be present in an inactive mode.
4. Under operation click edit and perform the necessary changes that you need to make.
5. Once you have make the changes associate the updated workflow to the respective project via project administration.