This merino situation has me fascinated and frustrated at the same time, so I wrote to her to see what her thoughts on the subject are. She has given me permission to use parts of her letter, and I think it will make interesting reading for American merino knitters who are experiencing the frustrating wait for Australian merino yarns.
That's a very interesting query. I have been looking into it a bit for my own research and writing purposes, and I think I can give you a short answer.
As you already know, we've had a series of droughts in Australia. Flock size is down over the last several years and overall, wool production is down somewhat. I don't believe the situation is considered a sheep shortage, however.
What has changed quite a lot, though, is the type of merino available. There's actually been an overall increase in the finest quality merino fibre (19.5 microns and under). Some of this is known as 'hunger fine' wool and is due to poor nutrition in the sheep due to the drought -- they produce less robust fleece when stressed. But some of it is also due to really good growing conditions a year or so ago in parts of Australia. It can take awhile for the seasonal ups and downs to trickle into the market.
So the combination of there being fewer sheep and each sheep producing a bit less wool which is finer than usual means the increase in fine merino has come at the expense of middle range merino around 21-22 microns which I imagine is what may be back ordered in NY.
I can't comment on the marketing campaign you mention as we are not subjected to it here! The Australian market is quite small and I feel the global market is usually the main focus of their efforts. (As you've seen in my blog already.)