To fill a position, you need candidates. To have candidates, you need students of that discipline. There are numerous issues that could skew the demographics of the students (some are problematic, but some may be natural/acceptable!).
And of course this applies to domestic workers. Global workers and importing talent via visas have different benefits and issues.
All that said, in my experience most DEI company policies are more about not getting sued and avoiding bad press. They create policies, but many of them are ignored or just turned into a spineless checklist. As an example, the article didn't seem to address why the Microsoft metrics are meaningful, or what the targets are and their justifications. There's no systems thinking approach to explaining why or how the metrics/policies are beneficial, rather it's assumed.