It will be on a benefit-by-benefit basis. Part of the reason for this is that other countries have tried different methods such as postal codes, geographic areas or groups of people. In our case, EI in particular is made up of seven core benefits, and we have to go one benefit at a time, because for seven years we will have to run the old system and the new system at the same time. It was too complicated technologically to do it differently.
On February 18th, 2021. See this statement in context.