WP and TRV should actually no longer be valid. Sometimes it isn’t automatic but there is a risk that when you show up at the airport you won’t be allowed on the plane with the TRV.
That's what i was thinking as well, his temporary documents may very well already be null and void.
It should be the moment he received his COPR.
This is why the PRTD is a much better idea, also gives IRCC a chance to ensure everything in the system is reset so that when he's going through immigration, everything is up to date on file and his landing is smooth.