I have been really wanting to mix things up here in Discedo, and this would definitely make Conan's life interesting, so I'm leaning toward doing it if we can figure out a way to do it without ruining their relationship.

I was thinking of possibly letting Ran get Shinichi's memory of that night at Tropical Land from when he ran off on her to when he passed out after Gin gave him the poison. That way she would know that Conan knows much, much more than he has ever said about what happened to Shinichi but she would still have a little detective work of her own to figure out what happened.