If the indexing is 7 speed and the rd is for 7 speed i could work. But who knows because I really cant remember if the cyclone pulled the same cable than shimano. Actually I remember seen a cyclone that was produced before indexing (friction), thats why somebody was asking what version of cyclone was.
If you have the parts to test that is pretty easy and fast. If you are looking to buy a cyclone RD is a risk because suntour had cyclone before introducing indexing and who knows, no idea if the suntour 7 speed freewheels had the same spacing than the shimano ones. I always used friction back in the day so i was able to put any of the wheels i had moving around. If you go friction mode the answer is a big YES, if you go index the answer is who knows.