Posting on behalf of my wife
I did my landing in June 2016 and have been staying out of Canada(in US). I’m sure that I will not be able to fulfill my PR obligations, hence will need to renounce my PR. My husband applied for his PR after out marriage (March 2018) independently and received a request to send his passport for stamping before May 12th, 2019 . He declared in his application that he is married and I will not accompany him to Canada.
My question is can I renounce my PR now and add myself to his PR before he sends his passport for stamping?
How did this go?
In short, the answer is yes, maybe. The timeline seemed pretty tight to get all of that done in time, but it’s theoretically possible. Here’s a later case demonstrating how to do this, How to Change spouse's status from non-accompanying to accompanying Post AOR | Canada Immigration Forum
If you do miss due to timing, it’s still not the end of the world as you can still be sponsored for PR as your husband’s spouse. See Sponsoring family mentioned as non-accompanying/unaccompnaying in express entry | Canada Immigration Forum for an example of that (sponsoring an unaccompanying spouse after PR is granted).