Hello
I have noticed some changes with donkeys and horses in 1.19.4. I'm currently designing a donkey parkour course and have spent a ton of time looking into movement mechanics. One clear thing that i can absolutely say has changed is the way donkeys interact with honey blocks. Weather or not this is intended I'm not sure, but when wall riding on honey with a donkey you lose height much more quickly than in 1.19.3. Another thing that seems to have changed is how frequently horses buck. there is a timed horse parkour which I've attempted to speedrun in the past. With the changes to bucking it's nearly impossible to get the target time, where it used to be trivial for me. A horse with the exact same stats bucks on nearly every jump where it used to only occasionally happen. Another player on the server confirmed that it felt abnormally tight. Anecdotal evidence I know, but there's genuinely something going on with that, I'm sure of it. 
Thank you,
-Mae