The page you linked is the landing page for the release notes. On that page, you can navigate to find the details for each specific version.
For VTune Amplifier 2018 Update 3, the direct link for the release notes would be: https://software.intel.com/en-us/intel-vtune-amplifier-2018-update-3-release-notes
The release notes were NOT posted for a couple of days. I got my first notification about the update on 6/1. I then started this thread on 6/4 and on 6/7 I checked again and the release notes were finally there.