This is incorrect. Ubuntu told me in clear words that dash searches will be sent after installation when I used dash. That's how I came to know of it, and that's why I disabled it.

I didn't like the fact that that it is opt-out and not opt-in, but yeah, way way better than Windows 10 for now.

Also note that Canonical took steps to ensure amazon doesn't get to imprint your system by proxying the requests through their server.