Yes he would be the obvious target for elimination in the traditional 1 for 1 NY fashion (do they lose 2 seats every time?).
But they key is that would save another Republican from getting it in his place.
I agree that if Turner wins this seat, it's quite possible that NY might eliminate BOTH Weiner and Lee's former seats. That would essentially make both "upsets" meaningless and be an effort on the part of NY politicians to hope voters forget about the fisacos that happened when Congressman resigned in 2011.
But whatever, a "GOP wins Congressional seat held by Dems since 1920s" headline would be worth it just to rub in the faces of the RATs who gloated they had a "mandate" on "Medicare, medicare, medicare!" when they won Lee's seat thanks to a phony "tea party" candidate splitting the conservative vote.