Hello there.. as per my understanding, once you get a request to submit your passport it is already approved. They just need it for stamping. I am not sure about the validity but my cousin got here 3yrs multiple entry until her passport expires.
Could you share your timeline, when you applied and how many days did you wait when you received passport request? bcoz i have pending appling too I applied online last sept27, 2017 and til now no response yet.
Congrats you will have ur canadian visitor visa soon.