Thanks Bryanna! But for passport submission, do I need to include his previous passport with the current visa? It doesn't state on the passport submission letter to bring the old one. And if I submit it, will they be stamping it with a "cancelled" message? Or everything is just updated on their database and Immigration Officer should be able to see that? I am really hoping my dad won't have any issue with the Immigration Officer, as he is already a senior and probably would be confused if he will be asked. I will be travelling with him but I don't think the officer will allow me to answer on behalf of my dad.
Quite honestly, it does not make sense. I assume he is traveling in the near future. There was no need to apply for a new TRV. With more than 9 months of TRV validity, IRCC does not normally issue a new TRV and applications are usually refused.
I can only think of these reasons:
1. Your dad applied stating his previous passport was damaged/lost. Probably not the case though.
2. IRCC has requested his passport NOT to issue a new TRV but to check for some other reason.
3. Your dad has a PR application in process
As he has already applied, just go with the flow. Do submit his current passport too along with the passport request letter, VFS consent form, fees, etc