I have a lot of games on Wukong and I never built trinity force or iceborn gauntlet. TF you can, but giving 3800g for an item that doesn't give you that much AD is just bad. Same goes for iceborn, it cost 1k less but it doesn't give any AD and it's only good for 1 hit with your Q before you ult. Following that logic, it's obviously just better to get an AD item that will help you with everything.
I always build full AD with few exceptions if they have someone really fed or someone that can burst you, then I get dead mans plate or steraks gage, you can get GA also.
My usual build is ravenous hydra - ghostblade - cleaver or maw if they have a fed AP - deaths dance or dead mans/steraks/GA.
I hate seeing people not going hydra on Wukong, you need it for wave clear, you can split push really fast and you need the lifesteal too.