No it isn't. In fact, in many instances this is the root of the problem. Outlook treats conference rooms like people with an email address. You "invite" the room to participate in the meeting and Outlook puts the meeting on the "room's calendar."
If the meeting is cancelled, however, it is rare for people to go back to Outlook and cancel the reservation. Consequently the room remains booked...and when the meeting time occurs, the room remains empty, denying its use to other people.
With OnBoard, if you cancel your meeting but forget to cancel your room reservation OnBoard can automatically return the conference room to the pool of available rooms, making it available for other people.
In addition, Outlook treats each room equally. (i.e. You need to know the attributes and furnishings of each room in order to select one that fits your needs.) OnBoard allows you to enter room criteria and and allows you to select space that meets the criteria and is available. OnBoard also lets you order special equipment or services needed for your meeting. Outlook has no such feature.