Per current documentation: https://docs.rws.com/en-US/trados-enterprise-accelerate-791595/completing-projects-741687
"When all the translation work is finished, mark the project as Complete manually."
My suggestion is that if the project progress reaches 100%, as in all files (in all languages) have reached the end of their workflows, the project should be marked as Complete automatically. It is odd that the project status will currently stay as In Progress despite being 100% and requires manual effort to update it.
I understand there are auto-Complete rules but I consider those rules to capture anything that's been ongoing for longer periods of time. If I have a project and I finish it within 30 days, it seems impractical to have to wait another 60 days for it to be marked as Complete or to have to manually set the status to Complete every time. With many users in the organization, it's also difficult to expect everyone to remember to do this manual step and as a result, requires frequent monitoring which could be avoided.
It seems much easier for everyone if the status just updated automatically to Complete upon reaching 100% finalization of the project.