So in that case, when systemd encounters a username it is rejecting, it should throw an error instead of launching the process as root. What happens when admin

So in that case, when systemd encounters a username it is rejecting, it should throw an error instead of launching the process as root. What happens when admin typos a username in this fashion? The system they think is conforming to least privilege suddenly is granting most privilege. Thanks systemd! It's like the code is as self-righteous as its author.