Is Editor Only setting excludes asset from map in packaged builds but does not exclude it from the package

Setting an instance of an asset in a level to "Is Editor Only" will cause the asset to not be present in the level in a packaged game, but the asset is still included in the cooked content for the game.

The setup in the reproduction project attached is a single map with a static mesh that is set to Is Editor Only. The map is included in the "List of maps to include in a packaged build" array and "Exclude Editor content when cooking" is enabled.

Regression?: No
This also occurred in 4.18

1. Download the attached project
2. Package the project
3. Check the packaged game's content
   Result: Cube.uasset is included in the packaged build's content
   Expected: Cube.uasset is not present in the packaged build's content because the only instance of it in the packaged level was marked as Is Editor Only