It's extremely doubtful CBSA confiscate it but Canada may be a sovereign nation they can do whatever they want. You are asking the wrong people call CBSA to get your info from the horse's mouth. Even then take the info with a grain of salt. I'll give a personal example I was born in Canada but have lived in the state for 99% of my life. Back in 1990, I lost my wallet, license, SS card, and credit cards the works.. Getting a new driver's license was a piece of cake, replacing credit and debit cards was relatively easy.
A replacement SS card not so much.. I went to the local SS office and the lady took my info and said I'd receive a replacement card in a week or two. I waited and waited but no card.. I called them up and was informed I was not an American citizen. I had to make a dozen or so phone calls until someone could tell me what to do. Which was contact the American Consulate in Toronto which had the original document filed by the State Department stating I was an American citizen born aboard.. So I had to make a dozen more phone calls navigating Canadian bureaucrats. Finally, I was able to get the document I needed. I went to the local SS office and applied for an SS card. The lady said we don't accept the document you have as proof of American citizenship..
Luckily I read the SS form carefully and at the bottom of the SS card application form it stated the form I had from the state department was a valid proof of citizenship and was valid to use to get a replacement SS card. I showed this to the SS lady and her response was, "Oh I didn't know that I had never seen one of those before", and with the press of a key on the keyboard, I was an American citizen again. After two months of fighting bureaucratic idiots.
The moral of this story is when you are dealing with the government any government you are dealing with idiots so use extra caution..