This provision is specifically about the right of employees returning from a strike or lockout to be reinstated to their jobs. What the amendment does is broaden who they have a right to reinstatement over, essentially, if that helps.
The way it's written currently, if an employer were to bring in a new employee in an emergency situation, as enumerated in subsection 94(4) to the CLC, then the returning striking or locked-out workers wouldn't necessarily have a right to be reinstated over that person, because that person wasn't used illegally. What this amendment would do is say that regardless of whether it was illegal or not, if someone was brought in to do the work of a striking or locked-out worker during the course of the strike or lockout, then the returning workers have a right to be reinstated over that person.