Did the brief, fatherly relationship between Tony Stark and Peter Parker still happen post-"One More Day"?
Does Tony Stark know who Peter Parker is?
So Stark doesn't remember why he invited Peter Parker to live with him or why they formed a father/son relationship?
And presumably he doesn't remember why he designed a suit of spider-armour for Peter, since as far as he knows, there's no connection between Spider-Man and Peter Parker?
Not a messy retcon at all then...