It means they will ship sometime in May. It doesn't take a rocket scientist to figure that out....
What kind of answers are you looking for? Obviously its taking Apple some time to get up to full speed and manufacture the products to meet demand. It happens every time they release a new product.
I'm not saying Apple is perfect, there has been some strangeness to this launch, but its not difficult to understand that there is a shipping range with every product and sometimes that range is a month or more...Apple USUALLY (not always but more often than not) gets products out to customers on the early to mid side of their promised date range.
I.E - I expect to see movement starting this week on band orders...for those that ordered right after the bands went on sale. And yes, there will be fluctuation on delivery dates depending on which band you order, just like the watches.
But who knows, I could be all wrong and crazy. 😀