The article doesn't mention how or what kind of location data will be collected/used. There is no explicit mention of tracking location using smartphones or laptops.

It is mentioned that the firm already uses location data in connection with billable hours (verifying/approving the billable hours, I'm guessing). Again, no mention of how/what location data is collected.

It is mentioned that EY does something similar (office attendance tracking) using swipe card data.