Losing in valiant effort/close game to any one of: tOSU, Michigan, or Wisconsin would not likely disrupt the mojo that Penn State has right now recruiting wise and from the perception of the media. Losing to more than one of these teams, or anyone other than these teams, will allow people to say: "see, I told you that 2016 was a fluke", and dismiss Penn State as a contender for the premier program in the Big Ten.
I'm not sure how much 1 game would mean in the big picture recruiting wise, but I guess it could affect the last few highly regarded and undecided players. After seeing the meltdown by some over the GA State field goal I have no doubt there will be many in the media who will pronounce Penn State a fluke or fraud contender if they get upset at Iowa.
I like JF's approach to each game. Undefeated is possible but not probable. How many recruits do you lose if you go 9-3 or 10-2? IMO none that you would want in your locker room for four years.