@Katayoon, I totally agree with you that cases are different and also that officer has the right to request a new one “if you travelled back to the foreign country between issued time and stage 2 request time”.Some countries put expiry dates on PCCs and officers reserve the right to ask for a new one when the time comes. Also, with HC taking often 2-3years, it is hard to project whether an applicant will not be back to his country (many people have deportation orders). So it is up to each applicant whether they want to submit from the beginning and then potentially re-do everything; or wait for IRCC to request it. In my partner's case, we just waited for Stage 2 and submitted at that point, which ultimately saved a lot of time because his first 2 HCs were rejected and he only got AIP from his 3rd attempt. This saved us the trouble of doing PCCs three times.
So, for a person who get deported, the PC will no longer be valid after expiry date it bears due to the fact that the person was present in the foreign country.
Kindly note that is the standard.
In my own case, my lawyer asked that we request at the time we submitted our application to avoid delays during stage 2 because it can be difficult to get from some countries. Mine came with 3 months validity as obtainable in my country and at stage 2, my lawyer mentioned in her note that we submitted PC already quoting the date and officer acknowledged.