Enabling the 'Deprecated' option in a blueprint's Class Settings causes all existing instances of it to be deleting upon loading any levels that contain the blueprint.
Found in 4.13.1. Reproduced in 4.12.5 and 4.14 Releases CL 3161689.
Result: Notice that any instances of the deprecated actor were removed.
Expected: Existing instances would remain.
There's no existing public thread on this issue, so head over toAnswerHub just mention UE-37283 in the post.