Hey, COPR letter is used at the landing time which has a limited validity. You will see it’s validity on your online account. Original letter is received when you send a passport, which is a PPR. Now, PPR step is skipped. Agree?
One should can keep original COPR safe since it’s one of the official documents. Make sense. But after you attend the landing interview at IRCC office or at the border, they send you the PR card by mail. You don’t need COPR then.
In our cases, since border are closed , passport can’t be sent, COPR letter that received treated as a landing completed. Hence you are going to PR card directly. We skipped the PPR & landing formality. Don’t expect any other document. And even if you get it, once PR card is received, that letter has a nice lifetime place in the documents folder.