Not automatically no, it can and is often used when blitzing, but it’s also used to spy, play robber, hcf elimination and commonly if you are playing vice on a wr.
In the cfl, cover 1 with a Canadian S is almost always purely Seam defence just past the hash on each side in a narrow, tall zone. Then you normally have a corner or half playing match zone and taking the deepest man any place up directly up the middle.