No. TN status requires actual Canadian or Mexican citizenship; permanent residence in Canada does not itself establish eligibility, regardless of how long the person has lived there or how strong the job offer is. The applicant's actual citizenship is the threshold question.
Citizenship, not residence, is the standard
Confirm what citizenship the applicant currently holds, including citizenship from a country of origin retained alongside Canadian permanent residence. If that citizenship is neither Canadian nor Mexican, TN is not available regardless of other qualifications. This is worth confirming plainly before any further planning, since it changes what routes are even on the table.
Confirm the citizenship plainly and in writing before anything else is discussed, because it changes which routes are even on the table. Ask what citizenships the applicant holds today, including any retained from a country of origin alongside Canadian permanent residence, and look at the passport rather than accepting a summary. Where the answer is neither Canadian nor Mexican, this route is unavailable regardless of the credentials, the offer, or the years spent living in Canada, and continuing to plan around it wastes the applicant's money and the employer's patience.
A clear answer at the first meeting also opens the more useful conversation about what is available instead.