Right now entity_load_unchanged() simply wraps a cache clear + entity load. In OO code it's not recommended to call procedural functions which live in the global scope, hence we need to inject the entity manager and retrieve the proper storage controller. Since the load unchanged logic lives only in the function above, OO code needs to recode it every time. Although the implemented logic is quite simple this in not exactly DRY.
See #1807692-82: Introduce a column synchronization capability and use it to translate alt and titles through the image field widget and below.