As the email says at the bottom, here are the release notes: https://git.savannah.gnu.org/cgit/emacs.git/tree/etc/NEWS?h=...
Or in antinews format: https://www.gnu.org/software/emacs/manual/html_node/emacs/An...
Personally though I've been running the igc branch... ;-)
The stability is not perfect yet. Sometimes it crashes but stable enough for me as a daily driver.
As the email says at the bottom, here are the release notes: https://git.savannah.gnu.org/cgit/emacs.git/tree/etc/NEWS?h=...