I followed the link using my G Suite for Business and consumer (gmail.com) accounts but instead of the Dashboard the Google Apps Script editor is opened. Could be something from my side that avoid that I be able to access the new dashboard?
At first I think that the problem could be a staged / scheduled rollout as this is something that Google does. Later I remembered that the cache and cookies stored in my device could prevent to see the latest features among other problems so I tried in incognito mode and this works so I deleted the cache and cookies, restarted my laptop and I was able to see the new dashboard. Then I leave the laptop for a couple of hours and when I tried again the problem occurred again.
Following the instructions on the referred announcement I tried to file a bug report but my access is denied, so I made a post on the Google Apps Script Community on Google+.
I found how to create an issue -> https://issuetracker.google.com/issues/71871414