I wouldn't freak out if Nebraska doesn't win. Not sure why anyone thinks Nebraska should “just win” this one. Vegas has it at -6.5, which isn’t “easy win” territory — it’s “one bad quarter or a special teams gaffe and suddenly you’re sweating” territory.
I think NU will win by 2–3 scores if they play clean. But it’s the first game of the year, on an unfamiliar field, against a respectable opponent. And yes, Cincinnati is a respectable opponent to face for your first game of the year. If this was Houston Christian in week 1, then yes, I would freak out.