Okay, so as it turns out - thankfully - you are correct. I called IRCC, and at the same time my wife emailed the Warsaw office. They confirmed that once a PR application is closed, the biometric info is automatically unavailable, but has no bearing on her entering Canada. They trouble is that they don't explain that, so we had a bit of a panic. Thank you for responding, and for trying to set my mind at ease. I appreciate it.
I was just looking at your timeline, and it is similar to ours in that you got your pre-arrival about a week before my wife got hers. Are you moving to Montreal, or elsewhere?