The revised requirements for grant citizenship require a PR to have the intent to continue to reside in Canada upon becoming a Canadian citizen.
Note, it is a requirement for a PR, for a Permanent Resident. This provision has no impact, none whatsoever, on anyone other than a PR applying for citizenship.
Thus there is NO impact on any citizen, regardless of when or how that person became a citizen.
No hint of any required residence in Canada after becoming a citizen (and if the provision did impose such a requirement it would violate the Charter, be invalid, and not enforceable).
Thus, again, this provision will have NO impact on anyone who is a citizen, regardless of whether they applied for citizenship before or after the revised requirements are in effect.
This requirement, however, is important and far-reaching.
It imposes a presumptive requirement that the applicant continue to reside in Canada while the application is in process . . . it does not absolutely disqualify an applicant who is residing or working abroad while the application is pending (given the upon becoming a Canadian citizen element), but it gives CIC and/or a CJ open discretion to reject an applicant who is residing or working abroad while the application is pending, since it is readily presumed that generally a person cannot intend to continue doing something he is not currently doing, so an applicant cannot intend to continue residing in Canada if he is not currently residing in Canada. (This is perhaps the main reason the Tories included this requirement, to definitively put an end to applicants-applying-on-the-way-to-the-airport.)
It greatly expands the scope of what is relevant for CIC to consider in assessing the applicant's qualifications, and in doing this broadens the range of facts and circumstances which are material. Far more than merely direct evidence of presence or absence from Canada becomes material information, and thus must be reported if requested. Omissions, as much as overt misrepresentations, will be grounds to deny the application or, later, could be the basis for criminal charges (thus potentially imprisonment), and could forever be grounds for revoking citizenship. This would be based on making a material misrepresentation (such as the RQ'd applicant failing to disclose an interest in property or a business abroad, failing to disclose an agreement to work abroad entered into while the application is pending, failing to disclose living abroad after applying, and so on . . . all fairly obvious stuff).
Beyond keeping applicants in Canada while the application is pending, the biggest impact will be on applicants issued RQ. The scope of RQ is likely to be greatly expanded, and the implications for failing to disclose information are for sure more important.
By the way: issues of intent are common in the law. There is an expansive body of law which governs evidence of intent and inferences related to intent. There is nothing particularly new or radical about imposing an intent element. The U.S. does even in its requirements to maintain Green Card status, let alone for becoming a U.S. citizen. The requirement does not open the door to conjecture or speculation. But as is common throughout decision-making processes governed by the rule of law, which of course Canada's naturalization process is, there are standards governing the range of inferences which can be made based on facts . . . thus, reasonable inferences based on facts can be (and undoubtedly will be) relevant to the decision-making in grant citizenship application decisions.