I see it more of a fast start to generate an MVP type of product because their are certainly still flaws in expo but the whole idea of not worrying about module updates breaking your app are huge. I personally use and like both but for different situations
'How to Build Tinder with React Native & Expo' It's a bit longer and more complex than what your asking for but I just finished building out a course learning React Native & Expo by building a Tinder clone https://www.udemy.com/how-to-build-tinder/?couponCode=LEARNR...
Finally! Every other major framework needs to jump on this bandwagon and stop supporting IE9 and then the users will realize they are outdated...at least I would hope so. Every aspect of Frontend development adds a ton of extra hours when building around IE9's quirks. I had the same idea as Bootstrap building my own Flexbox based CSS framework Useful.ly