Just my 2 cents, but having just been to the airport, I think this all makes a lot of sense. There is a significant flow of people now streaming in from the south because of the hotel/transit center. It really seems to have changed the way people flow through the terminal - no longer evenly from the east and west, but rather a clear flow from south to north. They actually had signs up saying something to the effect of "smaller wait times at North TSA screening checkpoint" because so many people walk straight into the southern checkpoint after entering the terminal. Not to mention the way that the gradual decrease in ticket counters actually being used over the last 20 years has changed how the terminal operates. The southern 3rd of the main hall is about the same size as the Union Station great hall, and would feel a lot more spacious if the TSA screening was completely removed. This, plus the new outdoor plaza, should be more than enough space for people waiting to pick up a friend. The remaining ticket counter areas would also likely remain open to the public.
And this is all before the question of modern security is even raised. Long, slow-moving queues of people in an
extremely exposed location aren't necessarily the best idea. I was just in Amsterdam where they use a much more efficient model that I've heard is being looked at for DIA.
Image from the Schipol Airport website.
Also remember that in the new configuration, you won't be forced straight to the concourse after clearing security, so people can move freely between the "clean" zone of the terminal and the concourses without the uncertainty of security wait times. Plus, international arrivals would exit into the "clean" zone and not have to do security again if they had a connecting flight. Even if the retail experience doesn't get much better, this makes sense from an operational standpoint alone, if you ask me.