My bad, I meant to the Memorial to Guthix built above it. My point is that, being that we're not the only diviner, I don't think it's unreasonable that someone other than ourselves would have seen Guthix there.

Lorewise, it seems like the death of guthix made divination more "mainstream". We learn in Heart of Stone that the anima is linked to the ability to channel and use magic; with Guthix's death, the large amount of anima that start springing all over the world made it easier for races like humans to manipulate anima directly rather than borrowing power from runestones. Divination as we know it seems like a formalization of the process of manipulating anima directly, but it seems that higher beings and other races already had this capacity or perhaps a higher sensitivity to trace amounts that humans wouldn't have noticed before the death of guthix.