Yes there is:
I have booked a suite guarantee on Carnival, Celebrity and NCL. On NCL it was a Cat AE guarantee and I was upgraded to an AC.
When I booked the suite guarantee on Carnival I was assigned an aft/starboard Cat 11. On Celebrity I received a Sky Suite.
They aren't on all sailings but they do have them. Just be prepared to get the lowest category suite. Also don't do a "mini-suite" guarantee and think you will get a full suite.