They definitely are, if they are still being placed on the market. I'm afraid you don't have a choice since the Date of Application - 26.5.2021 - when the MDD was effectively repealed. Any legacy devices being placed on the EU market after that date under existing MDD certificates are under the MDR transitional provisions.
I am also very certain that your NB needs to know that your Contract Manufacturer (that's not just any "crucial supplier" or "critical subcontractor") is moving to a new site! Regardless of MDD, MDR, "critical" etc.