That's because they're stored in your persistent data. Ren'Py when told to do so will keep hold of details across versions, like your name, your autosaves, and your gallery progress. The only time this will fail is if you're on a new machine, but even then, most of the data will transfer, it just might lose track between saves. You're not downloading the game for the first time, you're downloading the newest version, so your persistent data maintains throughout the files and you don't have to start over. ♥
Viewing post in Version 0.88 (Jun) - Public Release comments
It shows his name and age and Piano(?) under Likes, but nothing else and the description doesn't change either. Saya's updated to say she was born in Hokkiado after telling it to Jun, but Jun's still says "A boy who seems to be good at the piano. Yuuichi decided to give him a tour of the school. It seems he and Yuuichi are in the same class. He's kind of a lot...". I even noticed it's a bit of the same with Shoichi's and Keisuki's profiles, the only one that updated besides Saya's was Keisuki's age on his birthday and Yuuichi's age on his birthday.