Some doubt here about the Dear Margo reference. I think it was for information, not a direct reference to the letter her in DP.

I don't think disclosure is the issue: there is no indication that the friend who has bought the house doesn't know the story. It's just that the LW (or the BF) is being silly about the fact that someone would actually dare buy this place of horror that must become the inviolate perpetual shrine to his 3rd grade teacher.