He may be, but he hasn't officially been named COO and he isn't on the executive committee.
Anyway, what we may be seeing is design getting a little out of control. For all the silly talk on the Street that Jony Ive would be a better CEO than Tim Cook, it could be Jony Ive who is causing some of the supply issues by pushing the design envelope. Steve Jobs had a way of bullying engineering to pull off the seemingly impossible, but what people forget is that volumes were significantly lower than they are now. Would a Steve Jobs-led Apple have been capable of shipping 47.8 million iPhones last quarter, or would Jobs have made a last minute change that held production down even more?
People complain that the iPhone 5 and iMac aren't "different enough" from their predecessors, and that their predecessors were "thin enough." Nevertheless, these design changes did create engineering and manufacturing issues (Foxconn has said the current lineup is the most difficult they have ever manufactured for anyone).
Well if Ive is going too far and no one is there to reign him in Cook just gave him a lot more power and raved about him in that Boomberg interview. So I guess we'll see if giving Ive more power is a good thing or not...