The article kept saying HR was responsible but I don't understand why this wouldn't be split organisationally. A manager knows who is on their team (and when t

The article kept saying HR was responsible but I don't understand why this wouldn't be split organisationally. A manager knows who is on their team (and when they leave), it seems to me it would make the most sense to split the "groups" into teams and make the managers responsible for keeping their group up to date.