Why? It's a pre-order, it shouldn't run out (especially when they are advertising Play store credits with a pre-order).
Can you imagine if Apple did the same with the iPhone? People would lose their minds and there would be articles all around the Internet.
Pre-orders should never run out, even if they can't give a concrete date on delivery.
I don't disagree with you, but if you've ever ordered Nexus phones from Google the past few years, you should know what I'm talking about ( I don't know if you have or not). The ordering process whether it's a preorder or not has always been strange. That's why I said I was surprised it took this long. Everything had been going smoothly, much smoother than the past, so I assumed they had got better at doing this.
A lot of people, including myself, who really wanted the phone ordered I as soon as possible, because we didn't want to take any chances. Even ordering early is no guarantee that you won't be waiting longer than expected, or people who ordered after you will get their phone before you do.