Unfortunately, everyone's reaction to the "altered" Sarah wasn't as shocking as Jon had hoped. Apparently, everyone took Biff's apparent gay relationship in stride, as though it were no big deal, or rather, that they had known about it for a while. But that may have been because Jon specifically wished that only Biff and Sarah would see Sarah as she really was. And no one but Jon heard the wish, so only Jon knew that anything was different.
However, even though everyone else took it all mostly in stride, Biff and Sarah didn't. They may have both seen Sarah as she really was, but the way people treated Sarah now (since she appeared to them as a fat, 40-year old balding gay man) caused her to act puzzled and definitely a little weirded out.
Jon kept a close eye on them, as he followed them through the school hallway.