[IBM]

Apple's unit sales for iPad were declining YoY for a few years (after rocketing out of the gate) before they stabilized. iPhone unit sales have been more or less flat for the past 3 years (with YoY declines against comps). They still reported units during that period.

It's possible that they've decided to stop reporting unit sales because they're anticipating that they'll decline from here, but it's unlikely considering that this has already happened and they reported them anyway. The actual reason why they've stopped reporting units is because they're retraining the shareholder base to look at Apple and the ecosystem of products holistically.