The changes to the middle income tax bracket come in at incomes above $45,000. By definition, any Canadians who are below that amount are not going to benefit from the income tax cuts. If you think about this from a mixed point of view, there are measures in the budget that do support Canadian families with incomes below the $45,000. Purely on the basis of the tax changes that we are talking about, the tax changes only impact individuals with incomes above $45,000.
On April 14th, 2016. See this statement in context.