I think you're under a misconception about the end result of the project.  The Great Hall project will actually move the area on the 5th level of the main terminal behind security, and turn it into a shopping and dining hall.  

Having said that, I believe the whole concept is stupid.  With all of that space that's currently used for the overcrowded security checkpoints and the overcrowded ticket counters the idea of compressing those two things into a smaller space on the 6th floor is ridiculous.  Plus, one of the nice things about DIA vs. other airports I have used is that there are some decent choices for restaurants outside of security in the Great Hall.  This allows friends and family members to spend some time with their loved ones before they leave on flights.  

I agree with the DIA management that there needs to be a way to address the lack of good post security concessions, but this isn't the way.