What about that whole Green Day playing Dookie thing? Kinda surprised there hasn't been anything mentioned about this publicly in a bit. If that's still a possibility, I feel Green Day is an option (and most certainly the only time they'd be considered a possibility).
The B-52s / OMD / Berlin – 2019 tour dates Aug. 4: Los Angeles, CA – Microsoft Theater Aug. 6: Portland, OR – Oregon Zoo Amphitheater Aug. 7: Seattle, WA – BECU ZooTunes Concert Series Aug. 8: Missoula, MT – Kettlehouse Amphitheater Aug. 10: Bend, OR – Les Schwab Amphitheater Aug. 11: Murphys, CA – Ironstone Amphitheatre Aug. 12: Saratoga, CA – The Mountain Winery Aug. 14: Phoenix, AZ – Comerica Theatre Aug. 16: Salt Lake City, UT – Red Butte Garden Amphitheatre Aug. 18: Denver, CO – Fiddler’s Green Amphitheatre Aug. 21: San Antonio, TX – The Majestic Theater Aug. 22: Austin, TX – Bass Concert Hall Aug. 24: Houston, TX – Smart Financial Centre Aug. 25: New Orleans, LA – Saenger Theatre Aug. 28: Tampa, FL – Ruth Eckerd Hall Aug. 30: Ponte Vedra, FL – Ponte Vedra Concert Hall (OMD only) Aug. 31: Charlotte, NC – The Fillmore (OMD only) Sept. 3: Nashville, TN – Cannery Ballroom (OMD only) Sept. 4: Cincinnati, OH – Bogart’s (OMD only) Sept. 6: Greensboro, NC – White Oak Amphitheatre Sept. 7: Atlanta, GA – Cadence Bak Amphitheatre Sept. 8: Dayton, OH – Rose Music Centre at the Heights Sept. 11: Grand Rapids, MI – Meijer Gardens Sept. 13: Toronto, ON – Sony Centre for the Performing Arts Sept. 14: Detroit, MI – Meadow Brook Amphitheatre Sept. 17: Washington, DC – The Anthem Sept. 19: Philadelphia, PA – Mann Center Sept. 20: Mashantucket, CT – Foxwoods Resort Casino Sept. 24: New York, NY – Central Park SummerStage
The Reddit "likely" list is hella optimistic. Here's a list of bands who are LEGITIMATELY in the Midwest with Riot Fest dates open:
B-52s - 9/14 Detroit, MI; gap til the 17th blink-182 - 9/10 Detroit, MI; 9/14 Cincinnati, OH (confirmed for 13th via leaked press release) Cloud Nothings - 9/12 Maquoketa, IA; 9/15 Detroit, MI Descendents - 9/12 Minneapolis, MN; gap til the 15th Get Up Kids - 9/12 Maquoketa, IA; 9/15 Detroit, MI Dave Hause - 9/12 Louisville, KY; 9/17 Columbus, OH Neck Deep - on tour with blink-182 No Parents - on tour with Descendents Raconteurs - 9/13 Columbus, OH; gap til Oct (confirmed for 13th via Reddit) Red City Radio - 9/13 Kansas City, MO - gap til Oct The Starting Line - 9/13 Cleveland, OH; gap til Nov Streetlight Manifesto - 9/14 Silver Springs, MD; 9/27 Detroit, MI (confirmed for 15th via tour announcement, immediately removed) The Struts - 9/13 Dubuque, IA; gap til the 17th Taking Back Sunday - 9/13 Kansas City, MO; gap til the 19th The Whiffs - on tour with Get Up Kids and Cloud Nothings
In addition to the list of likely probable/suspicious acts above, Bloc Party has US dates around RF skipping Chicago. Nas is on tour with Mary J Blige, she's doing a solo date at Ravinia RF weekend, he's open. And of course Andrew WK & Gwar will be there as always.