The article seems to be saying that the study shows that hiring managers are able to identify with not a lot of interaction candidates that are well-educated, g

The article seems to be saying that the study shows that hiring managers are able to identify with not a lot of interaction candidates that are well-educated, gainfully employed and earn a high salary and unsurprisingly favors such candidates. This is not class bias - you can't just define class as that which employers care about and then accuse hiring managers of having a class bias when they understandably look for these traits.