Office 365 BULK UPN change and effect on Temporary password

[Marvin Oco]

if you provision 100 users via cloud and their UPN is in format USER@CONTOSO.ONMICROSOFT.COM, will the generated TEMPORARY password not be affected if we change the UPN OF 100 USERS to CONTOSO.COM?

[#2]

No, it will not. Remember to let them know about the new UPN value though, otherwise they will not be able to login.