The FIBB online league uses the OOTP Create a Fictional Player function to add "Local Heroes" to our worldwide teams as part of the Amateur Draft. I edit these Heroes talent ratings, but leave the age alone. Anyway, in OOTP6 patch 1 these created fictional youngsters are showing up with Years of Service despite the fact they are brand new and in single-A.
Look
here . I have to think this was just something overlooked as created minor-league rookies should not have any service time.