User.reassign_to() fails if the user owns a feature layer view. The error message is "Unable to reassign item. This service item has a related view or ogc service item".
You can use the UI to manually change the item ownership:
1) if you change ownership on the feature layer, both the feature layer AND the view get transferred.
2) if you change ownership on the view, you get an error "Some items were not reassigned because they have dependencies on other items." Neither the feature layer nor the view get transferred.
3) if you change ownership of the feature layer and view at the same time, you still get the error "Some items were not reassigned because they have dependencies on other items." But, BOTH the feature layer and the view get reassigned.
Buggy.