To be clear, they canceled the pre-orders in preparation for taking new pre-orders.

From Samsung:

Ensuring that you have the best possible experience with this revolutionary new technology is our top priority. We are taking the time to rethink the entire customer experience – from purchase to unboxing, to post-purchase service – so in the meantime, we have, regrettably, decided to cancel your existing pre-order. While not an easy decision to make, we believe this is the right thing to do.

Gotta say, this was not the smoothest of new product introductions.