High Speed Rail Alliance hosted a webinar with Amtrak to discuss the Union Station Access grant. They mention a couple new details, especially in the Q&A portion. Amtrak is planning a concourse and waiting area at Harrison St for the mail platforms, with a potential 2nd entrance at Van Buren St. This would mean you wouldn't have to go through Union Station to access the platforms. Ideally the Metra trains would use the mail platforms for through running between O'Hare and McCormick Place. Amtrak has started discussions with Indiana to increase service and speeds to Indianapolis by using the South Shore Line's West Lake extension.
• Video Link
https://www.youtube.com/watch?v=7D7i77mPAcg