Most Canadian citizenship applicants will be required to first establish Canadian tax residency

A Canadian citizenship applicant now will be required to have been physically present for four years in a six-year period and for at least 183 days per year in four of the six years, and to have filed Canadian income tax returns, if required under the Income Tax Act.  As noted by Kevyn Nightingale:

Now each applicant has an incentive to file Canadian tax returns. Without them, CIC [Citizenship and Immigration Canada] will have to determine they were not required. As a practical matter, CIC will likely consult with the CRA to make this determination, so anyone applying for citizenship will need to have their tax affairs in order.

Neal Armstrong.  Summary of Kevyn Nightingale, "New Canadian Citizenship Rules (Bill C-24) and Tax", CCH Tax Topics, No. 2190, February 27, 2014, p.1 under s. 2(1).