https://www.pcgamer.com/sekiro-hacker-discovers-cut-dialogue-and-alternative-dragonrot-system/

Dying repeatedly in Sekiro infects characters you've met with a mysterious illness called Dragonrot. You can cure every character's dragonrot at once with a Recovery Charm. Veteran restorer of cut content, Lance McDonald, has discovered that the system didn't always work this way. Using patches to restore lost code, McDonald finds Dragonrot Pellets that let you restore characters' dragonrot one by one. 

This method for curing Dragonrot was cut at some point during development, but restoring it unlocks new dialogue exchanges throughout the game. Dogen in particular has more to say. New dialogue options open up when you offer him the pellets, and he even talks a little bit about Emma.