I think that Wilson knew House could do it ordinarily, but i don't think Wilson understands just how much Cuddy has beaten him down with her manipulations and impossible-to-meet expectations. I think House was on the edge already so he didn't have the same strength and stability that he had when Wilson went under the knife.

I think Wilson was genuinely concerned about House and what would happen if he and Cuddy broke up. He knew there would be pieces and didn't want to have to pick them up--because he didn't want House to fall to pieces in the first place.