This is a ridiculous rationale. It's fairly clear from the sales numbers that everyone who was going to buy the Watch likely have. So unless Apple is planning only to sell to that same 15 million group of initial customers, then there needs to be a new watch to generate new interest as soon as possible.
There's currently a well defined and finite pool of customers -- essentially everyone who has an iPhone 5 and up, which is reportedly somewhere around 500 million active users. Which means, Apple has only sold watches only to around 3% off the potential customer base -- a customer base to which Apple has exclusive audience to target advertising e-mails, along with apps for the watch its customers can't delete! To say those 500 million iPhone uses are unaware of the Watch is ridiculous. So it's either too expensive, doesn't do enough for the value, isn't fashionable enough, or something the customer isn't interested in adding to their current digital experience. All of these things Apple can address with updated hardware.
Have you ever Face Timed on an iPhone or iPad? Those things are heavier and much more difficult to hold for a long conversation, yet people do it all the time. The watch may actually be easier to hold up, to the extent it's even necessary. Moreover, the watch is meant to be a convenience to answer such a call, rather than fumbling for the phone. Then after the call is initiated, Hand Off seamlessly hands the call over to the iPhone, or possibly iPad or even Mac. It will be a great addition. If it's too much trouble for you -- DON'T USE IT!
