Since the last two weeks you will see an change of the name of the Administrator Center. Microsoft change the name from “Office 365 admin center” to “Microsoft 365 admin center”. This is only a change of the name. All of the admin centers will be now Microsoft 365 admin centers in the Microsoft Global Cloud. This is more easier for Microsoft and for you, if you booked the biggest License M365 E3 oder E5.
View from my new Microsoft 365 Admin Center:
But the change need some weeks. You will see the name “Office 365 admin center” in some menues in this time, but it will change in the next weeks.