Greetings,
I am new to this forum and tried to reply earlier. Either my response was pulled because someone thought I was affiliated with a store or I didn't complete the reply process. In either case, the new cabinet that Boogie came out with for the Mark V is a 1x12 Widebody Closed back cabinet. It comes loaded standard with an English Made, Celestion Custom 90 Speaker. It is front ported and has a Pro Net of $469. While it is a small closed back / front ported cabinet, I am not sure if it falls within the official parameters for a Thiele design. My understanding is that Boogie doesn't get that specific about specifications these days. You can find a really good front and back view of this cabinet on Wildwood Guitars' site (I don't work for Wildwood - just noticed the nice photography).
http://www.wildwoodguitars.com/amps/mesa/1x12_cab.php