It's not evident yet but there are two layers of curation: relays and users. The relay (app catalog) is the main curation mechanism. The Zapstore relay may decide to remove certain apps in the future, but that does not matter, the whole point here is having the ability to manage your own app catalogs. (In the alpha version right now this is already possible) WoT will also be used to discover/recommend app catalogs. User-level curation is talked about more because (a) it's innovative, (b) it's prominent in the UI, (c) in practice there's a single relay right now