The link previously didn’t appear unless there was a new beta available. This didn’t make sense as the default release is tests-passed for which there are multiple changes almost every day.
Tests-passed sites aren’t expected to keep upgrading to remain on the bleeding edge in lock-step with those releases, but it’s still very useful to have access to /admin/upgrade without needing to manually type in the URL.
On the dashboard, the “Perform upgrades here.” link appears to have moved closer to the stats menu tabs. If you compare my screenshot with the one in the OP, you can see it used to be more obviously be near the version number, with less space above and more space below.
An improvement might be to change this into an Upgrade now button located on the right side, below the “You’re up to date” message.