Is there any risk in mentioning a new faculty as a potential advisor in you SoP?
I don't see any negative aspects to such a request. If nothing else it shows that you have a focus on a particular area of research. But in the US it isn't really necessary, almost everywhere, to specify a doctoral research advisor so early. 

I assume that a "new, but with tenure" professor in a department is well respected everywhere. People are seldom hired "with tenure" otherwise. Most incoming professors have some, probably short, probationary period with at least a pro-forma grant of tenure. 

As to the suitability of the person as an advisor, you should also look at their history of producing PhDs. I assume he is experienced at that, and if not, then you should probably keep your eyes open before you jump.