Like many words in the English language, “discrimination” has multiple meanings.

From Webster:

1. The act of discriminating.

2. The ability or power to see or make fine distinctions; discernment.

3. Treatment or consideration based on class or category, such as race or gender, rather than individual merit; partiality or prejudice.

You are talking about 2. The article is talking about 3.

3. is illegal in hiring. 2. is not.

ML is a technique for discovering and amplifying bias.

Applying ML to hiring shows a profound lack of awareness of both ML and HR. Especially using previous hiring decisions as a training set. Like using a chainsaw to fasten trees to the ground.