You can change it from the UI if the % complete is set to 'Manual', but you have to do it from the specific project you want to change since that is where the work is being done. You can't change the project status from the program view.
That is also stated in the answer of the KB article.
Answer:
If you set 'Duration' or 'Effort' for % Complete Calculation Method and run 'Update %Complete' job then the status of the sub project will be change.
Also, if the % Complete Calculation is set to 'Manual', you can update the overall project status field or individual task status fields by going into the specific project. You cannot update the status field from the Program Gantt view.