Step 4 specifically mentions application user:

"4. Create an application user"

The question asked with bin/add-user.sh is:

"What type of user do you wish to add? 
 a) Management User (mgmt-users.properties) 
 b) Application User (application-users.properties)"

You are right. However, I was going through the instruction again after some time now. I even forgot logging this bug. And I hit the same issue. For some reason this is not that obvious. From the usability point of view, I would suggest extending the instruction as follow:

"4. Create an application user (i.e. in the Application User domain)"

Please re-consider and close as needed. Thanks,
Martin

I don't see a harm in making the instruction more explicit, but this is definitely not a blocker for the release.