Implications of changing domain name in zoho mail for other zoho apps

Implications of changing domain name in zoho mail for other zoho apps

Regarding this post:  https://help.zoho.com/portal/en/community/topic/change-domain-name-in-zoho-mail-15-5-2015  can someone clarify what will be the implication to all other Zoho apps, for example expenses, crm, helpdesk, etc.

Are changes to the login information automatically replicated?

Does the administrator need to do something in order to update login information?

Does each user need to do somehting?