The cores are absolutely NOT in production. HBM2 will begin initial production soon (not volume). If they were stockpiling cores now, ready for Q1 '17 Tesla P100, the cores manufactured now as opposed to 9-12 months later would be obscenely more expensive. The only way they could ever justify doing that is if they forsee the design / process being so broken that it's not going to significantly improve in the next 9-12 months, meaning they have to start making them now to get enough non-defective units to launch a year out. That would be completely unheralded in the graphics industry, and probably bank breaking for them.
If they were in production he'd have showed test / chips cards.
They still can't even show GP104 chips / cards, let alone P100 Tesla.
Bunch of lies, again.
Fraid you are wrong on this (well sort of). Even if he was being crafty with the wording. Don't forget that HBM2 isn't the only configuration they are using Pascal for.