its just notice to all PR Holders to get Cards renewed or apply for PRTP if you are out of country and card is expired. thats wat it is. its got nothing to do with your spousal file
that is when they are scheduled to pick your file again. its almost kind of a reminder for them to see that file. lot people thought it was like a deadline but it is not.
mine is straight forward. but this is my second TRV i applied one before in april before sponsorship and got rejected due to travel history and all the usual reasons. I am not sure why this is taking too much time.