Does anyone remember the "kneeling" computer chairs that came out in the mid-1980s? Some of the same claims about promoting good posture. This seems like another of those gimmicks that won't last, assuming it ever gains any popularity at all.
As for anatomically male-friendly clothing, the best are kilts without underwear, which I've worn. Not only totally unrestrictive, but cooling, which is best for a man's junk (except in a Minnesota winter).
Just not very practical in the modern world, however, nor culturally acceptable in the US except for special occasions and when playing Scottish bagpipes. Too bad, I enjoy wearing them.
There's also a US company in Seattle that I first ran into when I lived there, that makes a more contemporary version of the Scottish kilt for Americans. Mostly gay Americans, from my observation. And you don't have to worry about having a sporran (that big pouch that hangs in front of a traditional kilt). Here's their link:http://www.utilikilts.com/index.php?page_id=46