When subscription on source server is deleted after migration do not remove DNS zone on slave DNS
After a migration the DNS zone for a subscription should not be removed from slave servers configured with Slave DNS Manager extension, if Plesk server is not the master for the zone.
Thank you for your input. We will consider this functionality in upcoming releases if it is popular. Everyone, please continue voting for this feature if you consider it important.
Just to add, that this is a vulnerability for any clients using multiple Plesk servers using the DNS extension as a platform for shared hosting. A client can add an already existing domain to their hosting subscription as long as they are on a different Plesk server to that hosting the target domain. If they then delete the domain from their subscription, this will delete the domain from the DNS servers, disabling the target domain.
Before a domains DNS is removed from the DNS servers by any Plesk server the removal script should check that the Plesk server is the manager of the domain in the nzf file.