I don't know about the Chicago market specifically, though I'd be fascinated to know what their security situation is there. When I was in Chicago a few months ago, I was shocked to see a WBBM live truck with full station branding on the exterior. Where I am, all of our live trucks are unmarked, and without going into too much detail, we take pretty extensive measures to ensure crew safety in the field.
While live-for-the-sake-of-live definitely still happens, we try not to do it. Usually, if one of our reporters is live somewhere for the late shows, it's because that's where their story was. It often makes sense for the crew to stay on the scene, finish their story, do the live shot, and then drive back rather than rush back to the station and slam something together to make slot.
A lot of stations are also just putting fewer resources into their late news and assigning fewer reporters to it. It used to be that the 10/11p news were many stations' bread and butter, but late news viewership is falling the fastest out of any daypart.