It's all in the details and takes time to work out. That's why people keep saying the impacts start now not in a year. All that planning takes time.
I worked with guy once where his department was outsourced. They rebadged him to work for the outsource contractor, and he got to bring his years of service with him. A few years go by, and the department was brought back in house. They rebadged him again, back to an employee. For the change back, he lost the years of service for the time he worked for the outsourcer. So, I worked with him for like 10 years, but he only had like 7 years of service. He lost the 3 while doing the exact same job but being paid by the outsourcer. Anything that was years of service based was impacted. Things like vacation time. He went from one company plan to anther and back but at a reduced grant all while doing the exact same job.