The simplest argument on this is, as it is required by MDR 2017/745 and the IVDR 2017/746 in their article 10.
Whatsoever, the UDI is to be applied to the medical device over it’s entire lifecycle. Thus, the UDI is not only affecting the development of novel products, but is to be incorporated in post-market activities and maintenance of the device.
Further, the Medical Device Coordination Group (MDCG), as an expert group of EU member states representatives, published a guidance on the integration of the UDI within an organization’s QMS. Even though the guidance from the MDCG is not binding, it gives another guidance on how to include the UDI into the QMS of a manufacturer of a medical device.