I have personally seen some companies divide the total facility across teams to try and focus on each team's ROI. Even non-core business activities like HR is spread across different teams so that the company has better view. I have found such optimisations to be an overkill. Because in larger scheme of things these costs are peanuts.

The same case appears to be with this company too. While it does sound great to have people not use meeting rooms for unnecessary meetings the bottom line effect is going to be negligible. The negative effect might be that either people will try to include as many as possible people to spread the cost or they might actively use their desk spaces for all meetings to avoid paying the costs.