Sometimes focusing on the meaning of particular terms is mere semantics, of little import, leaning toward distraction.
BUT other times the meaning of words makes a difference.
Whether or not someone "can" do this or that is a wide, wide open question, and other than, say, something overtly impossible, like can an individual personally lift an aircraft carrier over one's head, the answer is almost always "yes," but how and to what effect varies rather considerably, and often "yes" does not mean successfully so, let alone yes without negative consequences. For example, in the very early morning hours when the highway is not crowded, yes you can drive your super-duper sports car two hundred km per hour. You can indeed. There is, of course, a significant risk there will be an arrest, the vehicle impounded, and other inconvenient consequences. But yes, you can do that.
A more relevant question, in the context of this topic, might be whether the law or regulations, or IRCC policy, impose a make-in-Canada requirement for Citizenship applications. Similar, say, to certain visa applications which the rules explicitly require they be made outside Canada.
For PR card applications it warrants remembering that IRCC explicitly specifies the application must be made from within Canada. Yet, there is no statute or regulation prescribing this. And the courts have ruled that a PR card application cannot be denied on the sole ground the application was not made IN Canada. Yet, notwithstanding multiple court rulings as to this, IRCC continues to explicitly state the application must be made in Canada.
But even that question, whether IRCC in effect allows for Citizenship applications to be made from outside Canada, probably illuminates little about whether, as a practical matter, a *successful* application for Canadian citizenship may be made by someone living abroad and done without physically coming to Canada to make the application. (There is no doubt, however, that the individual MUST come to Canada at least twice during the process in order for the application to result in the individual actually becoming a citizen, and this may need to be done on rather short notice, with NO notice directly to the applicant abroad.)
The forum has seen isolated anecdotal reports by individuals CLAIMING to have applied from abroad and successfully becoming a Canadian citizen. If one trusts those reports, that suggests that it "can" be done and, more to the point, it "can" be successfully done.
Hard to know whether to trust those reports. Moreover, even if true, those reports offer scant contextual information and do not reveal, for example, how those individuals dealt with particular aspects of the process, not the least of which has been suggested by other comments here: what residential address and what mailing address did they use in the application. And, very importantly in regards to the latter, in regards to the address information provided in the application, to what extent the information submitted was truthful. We know, for example, more than a few citizenship applicants succumb to the temptation to fudge address information, many of whom get away with this, while many others run into problems as a result.
There are many, many what-if-this, what-if-that, factors which could have a big impact on how things go for the PR who is living abroad after applying, let alone already living abroad before making the application. The potential pitfalls are clearly many, just considering logistical issues alone, not to mention the prospect of non-routine processing.
It is fair to observe that, at the very least, a PR living abroad could anticipate some difficulties, if not rather steep hurdles, in pursuing an application for citizenship, with a very substantial risk, for this or that reason, the application will fail.
Just because you can drive 200 km/hour in the middle of the night on the 401 does not mean it is a good idea.
