Disable Azure AD Sync and Federation

Question

Hi,

I have to disable all Azure AD sync connections in a customer's environment.
User logon is forwarded to a portal that is not available anymore and users were synced with a local AD structure.
Since the local structure can not be accessed anymore without a lot of "roll-back work" I would like to disable the forward and
enable users to use the Microsoft login (portal.office.com) and use all the apps and data that is created already in Teams and so on.

I found a guide to disable Federated services but I am not sure if that is all I need to do and what will happen with users that are
already available and in use.

1 ) Open “Microsoft Azure Active Directory Module for Windows PowerShell“
2) Connect-MsolService – Enter Global Administrator Credential
3) Run get-MsolDomain and you will find that your domain is federated:
4) Convert-MsolDomainToStandard -DomainName Pelegit.co.il -PasswordFile C:\1.TXT -SkipUserConversion $true (The file won’t created):
5) Set-MsolDomainAuthentication -DomainName Pelegit.co.il -Authentication Managed
6) Get-MsolDomains:

In my case I would not skip the user conversion and set a new password for all users.

Can someone tell me if the conversion won't harm any data saved for the users in mailbox, the cloud and teams?

regards
Roland