Repo uses entity revision lookups and entity meta data accessors as watchers for entity changes to purge cache when entity is changed or deleted.

The structure proposed for dispatching services proposed in T148141 should take this into account.

DispatchingServiceFactory could implement EntityStoreWatcher interface, so its instances can be registered as watchers.
Entity change events should then be delegated to the service configured for the repo the entity in question belongs to. The service could then update its cache, so in the end dispatching lookup service would not use outdated cache.