According to the privilege page, they can:
When should I act on spam and offensive flags? [...]
That fact goes back all the way to revision #1.
But, is this still the case? Personally, I've never seen one, but then again, they're not exactly common.
Recently, I saw this answer in the flag queue with a single "not an answer" flag, but an unusual amount of downvotes (-5), which in my experience is an indicator of spam/offensive flags that carry an automatic downvote.
I'd say it was offensive to some, but since it was also completely useless, I decided to flag it as offensive as well, for the sake of bumping it off the site faster.
And, lo and behold, it was destroyed as such at -8, but I never saw an offensive flag on it.
Are normal users able to see spam/offensive flags? If not, since they clearly used to be, why was that ability removed?