Think about it:
Layla's power is to "know stuff". Her power allows her to know how storylines were before being retconned, and contact with her awakens those retconned memories from heroes.
Thus, what happens when Layla meets Spidey?
Wouldn't she remind Spidey that he was married to Mary-Jane, that they had a daughter, that he unmasked himself and all that other stuff that Mephisto erased?
How come Quesada didn't realize this?
How come Mephisto didn't realize this?
All it takes is a single Layla guest appearance to have this entire storyline come crashing down.
I've long maintained that OMD would be easy to undo, and this would indeed be an interesting way to do it.