The future of Arlington International Racecourse wasn't made any clearer Thursday when its corporate owner discussed the historic track and its other suburban interests with investors. During a quarterly earnings call Thursday morning, Churchill Downs Inc. CEO Bill Carstanjen reiterated the company's commitment to keep the Arlington Heights racetrack open through 2021 -- leaving its long-term future in limbo -- while he doubled down on a decision not to seek slots and table games once seen as a lifeline for the struggling horse racing industry.