This breach is them being irresponsible with customer support software. In the case of automated age verification, the providers say that nothing identifiable gets stored and they might be lying but it’s feasible that you could run that service the way they say they do.

This breach is about the manual alternative to that, where you can appeal to Discord customer support if the automated thing says you’re not the right age. They seem to do that in part by having you send a picture of your ID.

I’m sure in their database they’re then just storing the date of birth etc, but then they obviously just don’t bother deleting the private image from the customer service software.