I found it interesting that the seed the Daedra wanted from this tree was named Apocalyspse, though donèt know how Apocalyspse is defined in ESO
If the sacred seed that was given to the Firesong circle is the same as the seed that comes from the Dead Ash Tree in the deadlands and is named Apocalyspse then I wonder which of these meanings would be true of it. What would this seed's meaning become, the old meaning or the new of the below definitions..
https://www.etymonline.com/word/apocalypse
or maybe the Elder Scrolls would have their own entirely different meaning of this word.
for me I think the seeds might have no corruption to begin with, especially the one from the Dead Ash Tree, for it was cleansed by fire so I still think there is a connection of some sort there. A Daedra there wished this seed as well - though it wasn't told what for.