I did it over Christmas/New Years 2022/23. I mailed the package December 10, the payment for the passport was put through December 20, and, if I had been home I would have had both the new passport and my old one in my hands January 4. Since I had to go pick it up I got them both January 5. All this despite it going in during the Christmas rush and all of the extra statutory holidays. (Despite living in Ontario, my passport was issued in Surrey BC. My guess is that for mailed in applications, they send them to less busy offices.)
I think there was a spot on the application to ask for the old one back. I don’t think it was automatic, but my memory may be faulty.