Let me first profess my ignorance from the outset, but comes as a complete surprise to me that a non-Canadian citizen working outside Canada for a Canadian company would be entitled to any form of redress or union representation or employment protection inside Canada under Canadian Law.
All I know is that in my part of the world the prospect of a successful outcome for an employee in similar circumstances is exactly zero.
But I do hope those affected get all that they're entitled to without any grief from their employer what-so-ever.