You got added to a GC that Naruto had created.

Naruto: "Hey everybody!" Shikamaru: "Naruto, what is this?" Kiba: "It's a random group chat, obviously." Neji: "I think he meant why we're we added." Gaara: "I would like to know as well." Sasuke: "The Sand village guy is here too?" Sakura: "Wow, that's a surprise." Hinata: "S-so... What is this exactly?" Naruto: "It's a GC!"