My amateur sleuthing leads me to guess KY is enroute from PHX to Provo via (Ryan Smith's?) Gulfstream G650.
Consider:
This aircraft is departing PHX soon after KY's tweet saying he's on the way
This aircraft has had multiple trips to Provo and Phoenix in the last week. Also one to Lexington on April 14th?? Hmm.
Also a trip to Teterboro a week ago (NHL related?)
Scheduled arrival around 5:46pm
This is not just any private jet. The Gulfstream G650 is THE private jet. Those who know....know.