This question statement is about https://confluence.atlassian.com/cloudkb/changing-the-cloud-instance-url-address-or-migrating-to-a-new-cloud-instance-691011835.html
there was a time when Atlassian was really great company, but after reading this documentation to simply switch a DNS name there has to be a new instance created and data to be export/import sounds like something a company would have done back in the 80s? And also it doesn't support a domain of the account holder??
do you remember the time INTERNIC was doing domain registration process via email? this approach to me feels even more ancient.
I am seriously questioning the technology leadership of Atlassian now. I use to be a big promoter of JIRA/Confluence to everyone i meet. Reading this document made me seriously ill.
All good things comes to an end, and seems like Atlassian has come to an end.
You are marketing something call cloud, and this reminds me 20+ years ago how we (the internet) created a unix account and rented out public_html directory and charge people paid money for it.