In a Deltarune update far less cryptic than what we’re used to, creator Toby Fox revealed that the character-flavored teas players can buy in Cyber City in Deltarune Chapter 2 will be less useful in the next chapters. While the teas could once heal up to 400HP, they will only be able to heal 10HP in future chapters.
When exploring Cyber City, Kris and company come across a pink Addison NPC that sells name-flavored tea based on the current party members. The amount of HP restored is determined by the name of the tea and to whom it is given, with some teas restoring more or less HP. For example, giving the Susie Tea to Noelle will restore 400HP to her (as Noelle secretly has a crush on Susie). Giving a character their own flavored tea only restores up to 40HP, while giving Thrash Machine any of the teas heals it for 100HP.

Based on Fox’s update, it looks as though all character-flavored teas in Deltarune Chapter 3 onwards will turn into a new item called “Rotten Tea,” which only heals 10HP per use. Considering it’s been almost four years since Deltarune Chapter 2 was released, Fox might have wanted to account for lost time by realistically aging the in-game drinks. Those who hoarded their character-flavored drinks might want to use them now, as they won’t be as useful when the story moves forward.
Deltarune Chapter 3 and 4 are set to be released sometime in 2025.