I just don't see it happening at all.

a) taking up time and space for such a useless chore would be completely tonedeaf to the chaotic situation (especially in YYZ)
b) no need for such measures in an endemic phase
c) you would have to be out of your mind to actually leave the airport and go to some testing facility because you were randomly selected. No one is ever going to do this
d) no, they won't have the program ready in time