Interesting read. I think that even though they have (functional but overall pretty crappy) first party replacement apps for email, calendar, dialer, etc., their third party app ecosystem is not yet strong enough to support them leaving Google Play altogether. But they, by far, have the best chance of doing so in the future as opposed to HTC, LG and co.
Amazon can do it now because their content dominates the Kindle tablet experience and there’s so much of it, especially in the US. From what I’ve heard on podcasts and interviews, developers who support Fire OS have provided really poor feedback when it comes to creating apps for that platform. It’ll take more than a developer conference and new APIs to convince them to support Samsung as an independent platform. For now, Google will continue to receive a sizeable cut from Samsung device sales but it’ll be very interesting to see how Android handles Samsung going solo if and when it chooses to do so.