They have determined a deeper and much larger zone of hot rock acting as a feeder to the active reservoir capable of  erupting.  The original event for this volcanic plume was well to the west and produced a huge basaltic lave flow that covered a vast amount of country.  If as and when Yellowstone were to erupt, we can expect a repeat.  In the meantime we are certainly confirming the existence of supply.

There is no evidence that Yellowstone has been able to mount any other sort of threat in the meantime so while threats are hypothetical, the reality remains negligible.  That is real good for civilization and once we have underground refugia that can protect everyone, it will be of no interest.

Otherwise it is a great park that everyone needs to visit.