That's when the classification of the firearms would revert back to the prohibited status. Currently, under the law, because of the order that was made to deem these provisions to be non-restricted, they are non-restricted until this act comes into force.
So, the Swiss Arms and the CZ 858s can be imported into Canada. They can be sold. They're treated as if they're non-restricted or restricted, depending on barrel length. This date does not affect that.
The other firearms are prohibited, and they should not be imported into Canada or sold.