You have absolutely no idea whether that's true.

You appear to be basing your ideas on what Nokia does rather than any real world knowledge of logistics. Companies plan these things out. They know when their deliveries will get there. The dates HTC and Motorola gave are reflective of what they planned - when they planned to manufacture, when they planned to ship, when they planned for stock to arrive etc. You have this idea that a fixed date is basically the latest date possible when it's simply the one that's planned out.

The think is Nokia's logistics work exactly the same way. They know when they're delivering they just haven't structured their business such that they communicate that information to consumers. That is the problem.