Since there are eyes on this thread: Has anyone successfully linked their HA Cloud account with Alexa? I keep on getting "We were unable to link Home Assistant at this time."
You can try some of these troubleshooting steps[1]. If you are on Twitter or Discord, PM me (@balloob) your username and an exact timestamp that linking failed so I can forward it as another example to Amazon.
[1]: https://twitter.com/clstokes/status/1019039457339535360
Note: I use Echo Plus, which has the abilities to discover devices. Not sure if this works with Echo or Dot.