Currently, we have (en):
New Textpattern version {version} <a href=\"https://textpattern.com/download\" rel=\"external\">available for download</a>.
Since this gets eyeballs, we have another opportunity to prevent someone blundering through an upgrade if they don't reach the minimum ride height. Something like:
New Textpattern version {version} <a href=\"https://textpattern.com/download\" rel=\"external\">available for download</a>. Please refer to the release notes before upgrading.
Throw in a link to the release notes (prettied up as a page on .com?), perhaps a note for non-English languages that the release notes are in English, and I reckon that'll do it.