This is not due to be fixed, so I'm posting this so other users are aware.
I believe there will be an upcoming techdoc covering it too.
How to replicate:
Hope this helps
Thanks for sharing this, Andy
Reference TEC493685 : What are the rules for the 'Project - Modify Baseline' and 'Project - Modify Baseline All' access rights?
This article was created some time ago. It describes the current behavior and how you should configure the right based on the current design.
The article has been updated now to include the bug reference and status.