Though Dwight has plenty of secrets to hide from Negan, he might be able to buy himself an olive branch by hard-selling Simon as the biggest threat to Negan’s rule.
The mustachioed second banana is not only dead-set on killing off every other community, but he also publicly condemned the Hilltop’s Savior prisoners to be potential casualties of war, which is a double no-no.
(And Dwight’s continued survival would make this moment that much more explainable.)
For one, he’ll definitely throw Simon and the others further under the bus for killing off the junkyard folks, and he’ll almost certainly blab about Simon’s passive coup to attain control of the Saviors.