A tip from one of our loyal readers has partly confirmed the existence of an always-on display on the Galaxy S7 and the Galaxy S7 edge. Samsung's Theme Store apparently has a new theme called “Cuzco”. In one of the theme screenshots, we can see something that is very similar to an always-on display, with the background being black and the notifications displayed in white. Now this doesn't outright confirm the existence of the feature, but it's enough to go with, especially since we're just a few days away from the big unveiling.
This also hints that the feature might not be hardware dependent, indicating that older Galaxy flagships might also get it, perhaps with a software update. Of course, it's likely that we're reading too much into it, so take this with a pinch of salt for the time being. Samsung filed a patent for an always-on display last week. Further, a rumor from yesterday suggested that the Galaxy S7 might have an always-on display, which makes this particular revelation that much more interesting.
Thanks for the tip Diego!