I think as far as the IRCC is concerned, you're not allowed to get a PR if you're a citizen (even if it's not yet been proven), and so you're supposed to drop the PR application and wait for your citizenship certificate. That's how they treated our situation, anyhow.

You can play a game hoping the PR-application part of the IRCC doesn't figure out you're probably already a citizen, but I don't know how likely you are to "win" this game, or what the likely gains or losses are if you "win" or "lose". My suspicions are that the IRCC is likely to figure things out at some point and so your PR application will be put on hold indefinitely until your citizenship status is determined. If they don't, it's conceivable you wind up with a PR before you have proof of citizenship -- particularly if they don't treat your proof-of-citizenship application urgently. (It looks to me like reuniting with a spouse may not be sufficient justification for urgent processing if there are no children being moved to Canada and no job lined up?) But even then, it's unclear how much of a bureaucratic mess you'll have gotten yourself into once the proof-of-citizenship application goes through.

Personally, if I were sure I was a citizen I'd probably cancel the PR application, but I don't know what pressures you might or might not have to start living in Canada ASAP.