Let me tell you something.Thai boxing knees and elbows? ...Sure. Same goes for WC knees and elbows. They do the job quite well.
On the other hand, these days, I'd say some familiarity with Thai boxing clinch work is a really good thing to have. Just like having some grappling experience. Personally, I could use more of both.
I have no clue what WC has.... Nor do I have any reason to doubt that it's got a nifty set of skills at that range using those tools. It makes sense to me that a complete system would have such, so sure. Good on them, then.