Gerrit (and by extension, the hooks core plugin) supports a ChangeAbandonedListener and ChangeRestoredListener.
These were added in https://gerrit-review.googlesource.com/c/gerrit/+/72215.
However, there's no ChangeDeletedListener. Note that the ability to Delete Changes was added in 2.14.
Gerrit should support a ChangeDeletedListener, analogous to ChangeAbandonedListener and ChangeRestoredListener.
Ideally, it should make available, to an onChangeDeleted implementation, all the details of the original change (I am specifically interested in knowing the topic of the deleted change). A ChangeInfo would be the natural way to do this, but I'm not sure whether that is possible, since at the time the listener fires, the change itself is already deleted.