Hey everyone, I can shed some light on this because I was one of the students involved in bringing Nats to Cornell and I will be serving as events director for the 2019 tournament. It is confirmed at this point - our bid was officially approved by the national board of directors at their meeting this past November! Needless to say, all of us at Cornell are ecstatic.
You are also correct to notice that we had to shift things a bit later so we could accommodate finals and commencement. We couldn't host it the weekend of June 8 either because that's reunion weekend, but fortunately we were able to sandwich ourselves between those events with the approval of Cornell conference services.
Feel free to direct any questions or comments about the tournament to me!