With the new Rune Artwork...

Are the structures that define each tree world runes? AFAIK the current rune system is somehow affiliated with world runes - small, weakened fragments I think. Despite their unmatched power in the lore, however, there aren't many tales of them - I believe only Ryze has anything to do with them in his lore - and i think it would be cool to get some more story about these structures. They look like they could be world runes - or perhaps structures that hold world runes safe, the world runes actually being the keystone? (When you choose a keystone, part of the image changes). It would be nice to get some more lore on the world runes, as you'd think ancient fragments or pure primordial magic that once shaped the universe, with the power to reshape landscapes, would be mentioned a bit more in the lore.