Series6, Series6XT and Series7XT GPUs are all based on the Rogue architecture. Series6 and Series6XT go up to 10, while Series7XT can handle 11 with the feature pack. Sounds okay to me?
The author of that article has confused general availability of the IP (which is December 2014) with the timeframe when products will be available (12-18 months after general availability).
I don't know if you've noticed but your question has already been answered.
http://anandtech.com/comments/8457/mips-strikes-back-64bit-warrior-i6400-architecture-arrives/419569
The main purpose of SMT is to keep the CPU busy(/-ier), remove idle states and deliver sustained/better performance...