@HuanPhung-1568 As per this documentation, Prerequisite to use Microsoft Entra Private Access, Microsoft Entra Internet Access and Secure Access Essentials is Microsoft Entra ID P1 or Microsoft Entra ID P2.
As you mentioned above you want to know whether this can be used if one has Microsoft 365 E5, yes it can be - https://www.microsoft.com/en-in/microsoft-365/enterprise/e5?activetab=pivot:overviewtab Microsoft 365 E5 has Microsoft Entra ID P2 license.
Coming to the changes in UI, its in progress as per the last communication which i had with the product team yesterday.
Same doc - https://learn.microsoft.com/en-us/entra/global-secure-access/overview-what-is-global-secure-access has been updated yesterday.
Let me know if you have any further questions, feel free to post back.