I did read your post on the reasons. And I certainly agree that destroying your PR card after oath is the primary reason that they won't allow the oath to be taken outside Canada.Well, I still think it is very unlikely for IRCC to let applicants take oath outside Canada unless the situation very extenuating (if the applicant is terminally ill, for example).
I posted my reasons here =>
https://www.canadavisa.com/canada-immigration-discussion-board/threads/october-2020-citizenship-applicants.704665/post-9525577
We were just discussing hypothetical methods that IRCC could use if IRCC were to decide that applicants can take oath ceremonies outside Canada. The other way, in addition to the one mentioned above, would be to allow the consulate to print Canadian Citizenship certificates instead of mailing it to Canada. These policy changes might take a LONG time to be implemented.
Any change in immigration policies that affect all consulates and embassies worldwide will definitely take a long time in coming.