The WS-15 should be completed within the 2020-2025 timeframe. Last year, there was an official report of a vibration issue that needed solving. Apart from that, the program seems to be going smoothly. And yes, they probably upgraded the tech specifications. If you want the original specs published in the early 2000’s, search for YWH-30-27. I’ll list the specs here ...
- 30 kg/s corrected air flow
- 175 kN wet thrust/ 110 kN dry thrust
- 6 stage HPC
- OPR around 6-7
- 1900K turbine inlet temp
- TWR 10
Basically, you should expect specs at least equal to the ones presented above. They’re pretty decent but I believe that the Chinese can improve on these by 2020 given their huge strides. But don’t expect any huge improvements or surprises ... as for lack of info, just wait. Last November, the J-10 TVC popped out of nowhere from a cartoon artist. Expect something similar with the WS-15.