Didn't he remember it when he woke up in Mab's lap?
He makes two comments indirectly mentioning his suicide, but he never explicitly tells Mab he arranged his death.
the first quote is of Harry's thoughts.
"I hadn't escaped her. I hadn't escaped what she could make me become.
Oh, God.
And all the people who'd gotten hurt, helping me . . . They'd done it for <i>nothing</i>"(474 US Hardcover GS).
Since he is talking about not having escaped Mab, it is reasonable to think that he remembers his plan. But he could have been relieved about escaping her at the start of GS, since it WAS a convienient side effect of being dead.
the second one is slightly harder to refute, as Harry talks to Mab.
"Guess . . . you're kind of upset with me" (475 US Hardcover GS).
But I think its plausible that he just meant that Mab would be upset at him for coming so close to death.
Right after that Mab talks about how Harry cheated her, although we don't see his reaction to that. It's possible though that Mab is just assuming Harry cheated her without proof, because IIRC Harry never talks to her about it (and Harry said to Molly that Mab would know if he was lying [implying he would have to tell Mab something for her to discern if he is telling the truth]).
Anyway I think that he will remember, mostly because I think he needs to make amends to Molly. But its an interesting idea.