CRA considers that s. 94(10) can impose a a retroactive obligation on a non-resident trust to file returns for up to five previous taxation years

A previous long-term Canadian resident left Canada, made a contribution more than five years later (say, in 2010) to a non-resident trust with Canadian beneficiaries, and then returned to Canada in 2015, less than 60 months later. CRA indicated that s. 94(10) would then apply to all the post-contribution years, i.e., 2010 through to 2015, to deem the trust to be resident in Canada in those years. Consequently, it would be retroactively delinquent for having failed to file (and pay) the requisite returns (and tax) for those years.

Neal Armstrong. Summary of 19 September 2015 STEP Roundtable, Q.7(b) under s. 94(10).