It wasn’t intentional, but apparently today is all about animal races. I guess that’s not surprising 10(-ish) of the 33 races in Monsters of the Multiverse are animal races.
I did change the URL for the Yuan-Ti to reflect the name change, but don’t worry: If you have the page bookmarked the site will redirect you.
There are few big impactful changes here. Aarakocra’s speed got nerfed and replaced by Gust of Wind. Kenku’s skill stuff improved and Mimicry is less painful. The Yuan-Ti got a name change and a small nerf. The Tortle remains a beautiful and spectacular wonder.