About 7 years ago I had the same discussion about using all cores (multi CPU/GPU engine), but some people had the argue that it would need a complete rewrite of simulation engine and it might take several years, and by the time that it is done we would not even have PC ...!
As of today we still have PC, and with new technologies like VR there is even more demand for optimization and utilizing every single bit of hardware.
Back then ED had 55 employees, now that they have 120 it seems it is a possibility. as we need our DCS forever :)
I hope by 2020 ED finish the acquisition of UNIGINE (another Russian company) and integrate the simulation engine, the most realistic, most optimized engine ever :)