You are correct. I did a little research and my understanding came from this Bloomberg article which said:
(full article
here
Of course that's not the same as Apple saying it on the record. However, reality is, it is an accessory by definition of the word since it requires an iPhone for full functionality. And while Apple does list the product separately on it's web site, that is so consumers can easily find it. Financially they are hiding in a category with other lower volume/revenue products. Apple definitely needs to manage expectations because much of the tech world is anxious to knock Apple off its pedestal. So it makes sense for them to soft pedal expectations right now.
Apple sold 125K iPods from the first day of release mid-Nov 2001 to the end of that year. Nobody cared. If Apple sells 125K Apple Watches it's first weekend it will be declared an instant bust.