The point in the article is more subtle than that. AIUI that's what happens in Hungary too. But he has to hire someone else whilst she's on maternity leave (and though it's not mentioned, that recruitment process itself could potentially be quite expensive), and then, when she comes back, he now has to fire that replacement person (which is slightly tricky, as Europe doesn't have 'at will' employment practices, so either there'll be severance payment involved, or he could hire someone on a more temporary basis from the outset, but that's almost certainly going to be at a higher rate). And then, the mother has accumulated holiday days all the time whilst off on maternity, so will either take them all off at the point of official 'return', and thus he'll have to be paying two people for the job at that point (or else she doesn't take them all at once, but takes them in large chunks over the next few months, making it even trickier to have someone else cover).

How does Canada handle those parts?

I don't know the best solution, and I bet there's no perfect one. But for many qualified jobs, employees are not easily interchangeable. You cannot replace and reemploy women based on their family needs without disrupting the business needs. Unless you provide employers with a solution to this, there's a disincentive to employ women in non easily replaceable positions.