You probably won't even have to validate then. I guess they can safely assume that you didn't create your account when you were 7 years or younger. They said they expect 80% of users or so to be auto-verified by some other means (account age, typing statistics, whatever)
to be fair, you don't need a credit card to create a Discord account. And yes, I don't think there are ZERO seven-year-olds on Discord. I just think the number is pretty dang small
