Thing is Google has never learned and done better on shipping their phones in years. Way back to the Nexus 4 launch, it was super popular and sold out immediately in November, took till mid January to get decent inventory, and then not easily available until like March.
Nexus 5 same thing, very popular, out of stock and hard to get for a good couple months after launch
Nexus 6P again, great price, great phone. But wasn't easy getting the right color and GB size you wanted for months.
Pixel XL, more of the same again, was sold out FOREVER, and restock supply was damn near impossible to get. Even Verizon had like 6+ week lead times on it, and this was after it was officially out and for sale for three months already, and was still backordered all the time.
You see a trend here ? I always thought the Nexus / Pixel line was just some pet project for Google, that they threw several million to the Google nerds in the basement HQ just to make some phone they thought Android should be. And oh yeah, let's sell a few of these to the ultra [H]hardcore geeks, that will actually buy them.
My point, I don't think Google bosses really give two sh!ts how many Pixel phones are made. Only the Pixel engineers themselves care, but the big wigs in Google look at it like whatever.
Google doesn't make money off hardware, it's not their thing like the iPhone is for Apple or the Galaxy line is for Samsung. So Google will never really push the Pixel phone, and will never try to get millions of inventory ready. It will be, yeah we have this phone, and maybe you can buy one, but we just like to show it off really.
Pixel 2 will be the same thing. Low inventory and hard to get the exact color and size you want for months. And then 6 months later still be a $800 phone, but not competitive to the next gen 2018 phones out at the time.