There don't seem to be many (or any?) carbon wheels for 9 speed bikes
Any Shimano compatible 10-speed wheel, other than a very few with special deep-splined aluminum freehubs such as WH-7800, can take any 9 speed Shimano cassette without additional spacers.

Shimano 11 speed road freehub bodies are longer and require a common 1.8mm conversion spacer to put a 10/9/8 speed cassette on. Many wheels come with this spacer, or a generic one can be used. 11-speed road cassettes do not fit on 8/9/10 speed freehub bodies, although some machining hacks can allow it in some cases.