I followed your steps and here is how you can find the release notes for the internal builds when you get them through the Visual Studio notification:
When you see the notification, you click to the "Get Now" button (see picture1). Then you get to a window, showing the latest version. On the right sire there is a link to the release notes for this version (picture2) and below are inputs for your Telerik Account log in credentials.
Another approach is to log in to your Telerik Account, from Manager Product select Latest Internal Builds and once the Available Downloads are displayed, you will see a link on the right side of the grid for the version notes.
the Telerik team
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