both are different camera for different purposes,i would say.
but 7D2 is indeed a better specs camera compare to 6D,probably 6D wins in FF but not everybody wants a FF.
i believe 7D2 will be a hot-seller.
There's always a position for crop cameras in the market. Esp the ones with lots of cross type af-points (coupled with a good AF module) and fast fps for the sports enthusiast or birders.