There is nothing proving any key was backdated. Starting in 2005/2006, it became clear that SHA1 was weak and that alternatives should be used.
So Satoshi knew SHA1 was weak, so he generated 2 keys. He used the weak key publicly, and didn't use the strong key. How does that make any sense to you?
Both keys were stored in a lockbox locked via a skeleton key hidden under a rock near Satoshi's front door of his home.
Wait... What?
Ha-ha, you just got GG'd.