Plus ça change, plus c'est pareil.
It seems that the writing is on the wall: the swappable battery and the SD cards so commonly found in phones (and tablets) are going away. They've historically been included because they've been included elsewhere; their inclusion once made a me-too product differentiator. And, for some--but not all, evidently--a deal-maker. Now they're being excluded from flagship offerings. When there's a version (of the S6) with the battery and SD card options built in--if it comes at all--, it will largely signal that these two features play second fiddle. Eventually you can expect them to disappear entirely. Get used to it, I guess. Apple pointed the way, and others are following, albeit at a distance.