Quite frankly, it is not as simple as you're making it out to be. People who got their COPRs re-approved and got their passports re-stamped, and have NO Authorisation Letter, are NOT "exempt". It is completely the airlines' discretion whether to consider the old expired document. I'm paraphrasing my consultant, who works at one of the largest Canadian immigration consultancy firms in North India: "IRCC has no idea what they are doing. There are internal conflicts within their departments, and no coordination whatsoever between teams."
You say that why is Canada issuing people COPRs - "to keep them in lockers?". Well, why was IRCC issuing COPRs after March 18th at all, when the lockdown was announced? They continued to accept passports and issue stamps until 23rd March. There are approximately 2000-3000 people like me who got their COPRs between March 18th and March 23rd. So why were we issued PRVs? Why are new COPRs being issued today, with an accompanying note clearly telling the beneficiary "YOU CANNOT TRAVEL".
IRCC's actions are nothing short of scandalous here. They are toying with people's lives, denigrating them everyday, and there is no accountability.