The first client of the ORES hooks inside mediawiki would be the EventBus, but I could imagine them to be useful for a lot of extensions. Let's discuss the possibilities and the exact API here.
The first hook might be something like RevisionRecordScoreSaved, however, given that @Halfak said about user scoring and potentially more entities scoring the name. of the hook is up for discussion.
This is a placeholder task for us to discuss, we will expand the description as we go.