Adding a new Directory to Monitor to the Auto Reimport settings for the Editor results in any Editor windows on the primary monitor being moved behind the top-most window on that monitor.
RESULT:
Any Editor windows on the primary monitor are moved behind the top-most window that is already open on that monitor, and that window takes focus from the Editor.
EXPECTED:
The Editor keeps focus after the directory is selected.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-45682 in the post.