I'm a bit confused - when i see these signups, they look like this to me:
rtwnj6tj7@privaterelay.appleid.com
rtwnj6tj7@privaterelay.appleid.com
> Starting later this year, new Sign in with Apple addresses, previously issued on privaterelay.appleid.com, will be issued on private.icloud.com. Existing addresses on privaterelay.appleid.com will continue to work and forward mail to users without interruption.
> After further consideration and reviewing community feedback, iCloud+ Hide My Email addresses will remain on icloud.com.
A lot of those are Hide My Email aliases that, by design, you can’t tell apart from real human addresses.