CPU-world reported +20% EUs for GT1-GT3 Broadwell, so yes the GenX diagram from HPG2012 could belong to Broadwell/Gen8. Based on 96EU @1 Ghz we might look for 1,2-1,3 Tflops for the faster GT3 parts assuming frequency can go up to 1,2-1,3 Ghz. At least Broadwell-K with high TDP should hold it.
Where do you get 96 EU's from? 20% on top of Haswell GT3e is only 48EU's and at 1Ghz that only comes in at 768 GFLOPs