The preview destination state is obsolete when transitioning to Exit node or a state machine

Repro:
1) In the Base Layer create a state and a sub-state machine
2) Make two transitions from the state - one directly to the state machine, and second one to the exit node.
3) select these two transitions and notice that they have an empty drop down list in the inspector for choosing Preview Destination State

If you do steps 1-3 not in the Base Layer, but in a New Layer or a sub state machine, you'll see that instead of the drop down list a message is visible:
"Cannot preview transition, must at least have a motion on either source or destination" - this is the desired result for motionless transitions (to Exit node, to state machine) in the base layer as well