Dynamic Planet and Rocks. I don't see why they would do this, and as a result, it appears Princeton and Yale Invitationals are using the same schedule.
I'm sure that the tournament directors would not change the conflicts. While it is inconvenient for most teams, the conflict imposes the same restrictions on all teams, and therefore is fair. Many competitions try to match the national tournament's schedule, and for that reason many teams have already adjusted to the conflict.
While this conflict may seem ridiculous, there have been much more arbitrary schedules in the past (2015's national schedule was entirely based on the alphabetical order of events).