@J.Aeby, Thanks for posting in Q&A. Based on my researching, the Microsoft Entra password policies set is for org. If you want to change it for a set of users, you can use Update-MgUser to configure password expire for users. Here is a link with more details:
https://zcusa.951200.xyz/en-us/entra/identity/authentication/concept-sspr-policy
Hope the above information can help.
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