It's based on Gamestop's own pre-order numbers.
We had months and even years of Nintendo fans believing every Twitter rumor about the NX, including incredible ones like "The NX could have more TF than the PS4", but an insider says that the pre-orders for the next Nintendo product are lower than expected and all of a sudden they ask for a certified personal letter from Kimishima to approve the OP... 🤨
It's an insider from a store, nothing top secret, and we get this kind of info for lots of games. It's usually viable. Chill out guys, saying that the next product has less pre-orders than expected isn't a personal insult, it's not exceptional, and it's not anything absolute either...