Illinois has been talking about this service for more than 10 years now. I have a feeling it's never going to happen, but you never know. Back in 2012 when we started doing a Trails & Rails program on the Southwest Chief... I remember pointing out the crossing where the connection would be to passengers on the train. 10 years ago and really nothing has been done... a bunch of talking and studies. Same with the service to Rockford, Galena, Dubuque, or wherever it is going now. The problem is if a democratic governor is in... it seems to progress... then a Republican governor gets in... and everything is cancelled. Wisconsin had the same thing with service to Madison and a state train from CHI to MSP via MKE. Maybe if Illinois stays democrat in 2022 and 2024 this could happen, I guess.
As much as I like rail travel... I don't know if service to the Quad Cities is needed. You can drive Chicago to Moline in 2 hours and 28 minutes. Rail would take significantly longer.