Virtualmin > changing name of domain?? A few questions

Virtualmin
1

There is an option on vritualmin to change name of an already installed domain ei CHANGE NAME OF DOMAIN??
What happens if the domain name is changed and USER, DIR admin are exactly the same?
Eg. domainold.com becomes domainnamechanged.com On all features >> apache, dns and mail and other services?
I need to confirm it before doing it as I may have misunderstood its real usage.

Please kindly help me what is the real purpose of the DOMAIN NAME CHANGE?

2

I want to confirm that changing domain feature of virtualmin does work with precision as it is designed. It was fast and easier way to rename a domain than creating a new one saving some time.