If a person dies in 2019, the legal representative may choose to file the final return at any time after the date of death. The returns will generally be processed at that time as a service to the estate. In these cases, the returns will generally be processed using tax legislation applicable to the 2018 tax year. The legal representative can then request a reassessment of the return in the following year (2020) to apply any tax changes introduced for the 2019 tax year.
As it says “…using tax legislation applicable to…2018…” you would use the 2018 T1 module in TaxCycle. And, remember that an “early filed” return is not eligible for e-file, so you will have to mail a paper copy. Include a cover page or something clearly stating this is an early filed return for the deceased.