This is not a shock as Endorsement had missed workouts the last few days and hadn't put in a published work since April 17th.
The defection of Endorsement opens the door for Backtalk to draw into the Derby. Should Interactif not enter, either Make Music for Me or A Little Warm could drawn in, as well. Make Music foe Me is currently entered in Friday's Grade 2 American Turf on the Kentucky Oaks undercard.
UPDATED: Interactif is out of the Derby, as expected.