The search on your device will dominate the user experience. Whether this is going to be Google, Siri, Cortana is really irrelevant. The AppStore itself will never know about context of the app and the closest you get to this is what Google currently does with application deeplinking (and now Bing/Yahoo and Facebook are following).
An app will just serve the user's context - today it might be News24 for news, but tomorrow it can be NYTimes or CNN. The same applies to shopping or any other use case.
FWIW - this quote is only "half-true":
“We [Naspers] are ranking in the top five with most of our e-commerce apps.
Yes, as Naspers, you own a large number of foreign owned/funded e-commerce apps, but none of your locally produced ones have actually succeeded. The exception is OLX (founded by Fabrice Grinda in 2006 and bought by Naspers in 2010), which currently receives competition from Gumtree/eBay, but in the next few months will also have to face another Rocket Internet startup in South Africa. Many of the other locally produced Naspers e-commerce outlets have either closed down (Kalahari this year and last year: SACamera, 5rooms, Kinderelo and Style36) or are busy winding down (you know which ones).
An app-store is no more than a directory of apps and itself has zero knowledge about the taxonomy of an app or what it actually does. An app itself is just the carrier of information and neither app-store nor app will exist for long as over time those will morph into IoT (internet of things) and become more context aware - you are going to shop on your TV, order groceries from the fridge, your appliances will order detergents etc - sounded all like sci-fi a few years back, but has already become a solid reality.
