I'm not sure how often this was used, but I personally liked this feature, and I was a bit sad to see this didn't make it in the Steam release
#Re-add Low Health Sound option
primal echo
radiant dagger
It's actually still in the game, just not in any settings menu. You can re-enable it with tf2c_low_health_sound 1, and configure what percentage it plays at with tf2c_low_health_sound_threshold.
I put in a request for this here: https://discord.com/channels/196337717267791874/1467043622229774337
primal echo
Huh, odd