I see teammates who are just now hatching older festive dragons because they started doing the Festive dragon line.
These dragons are already hard enough to level up because of the rarity of their shards. But they will never have the runes and glyphs that were released with them.
Potentially have the gold chests choice nodes in the festive branch give rotating choices of past festive runes?
So one season you may have three nodes where the choices are
Gold Chests, epic for hueso, nebulon, azrael)
Gold Chests, legendary for hueso, nebulon, azrael)
Gold Chests, mythic for hueso, nebulon, azrael)