Isn't the aurora store just a wrapper around the play-store using an anonimized account? That is exactly the reason that google can easily block them. They obviously found a way to stop the burner accounts that Aurora makes from accessing the store. It would be equal to making a container for each time you renew the anonymous account.

In other words, unless the aurora app has a backdoor (and I believe it is FOSS, so that should show itself easily), it is as secure as the play store ( which has debatable security, I believe it served malware on several occasions )

But please correct me if I'm wrong