When replacing an oil pump, why would the oil lines need replacing.

Hello, as you know, this vehicle has a V10 engine that is of exceptional high performance and precision build. I personally cannot claim to be a BMW engine expert, but in my brief research, I see this engine utilizes 4 oil pumps for use during different driving scenarios, and has a high degree of engine build complexity. I did see that in 2006, there was a service bulletin addressing the oil lines for possible need of replacement due to their manufacturing, but I am certain 11 years later this is not an issue. In any case, I would strongly recommend you consult your service consultant or even service manager or shop foreman at the BMW dealership to gain some clarity as to why the lines are being recommended. They are experts in their fields and should be able to give you the explanation you need. Good luck.