In either Workplace or Review Bookings (ab-ht-booking-review.axvw), allow the one making the cancellation to enter a reason for why the booking is being cancelled.

It could be either from an administrator, from a team lead, booking requestor, or the one being booked for.

Reasons can vary from any number of reasons. Examples could be, "the room is no longer needed", "the floor will be undergoing renovations at that time", "the space is required for a special event", "the room was booked in error", "staff member X booked a desk for me, but I want to use a different desk".