It depends on where you are, and for some countries only certain % of the population will get it as it ramps up slowly. For some products, the new isn't ready so it falls back to the old stack. It could be due to the ramp, WIP, or just that the old code is too old to the extent no one wants/dares to modify it.
We get sort of half old, half new, depending on where you click. Neither interfaces are any good though.