For Microsoft.Management.UI.Internal, we ship it and own the code, so I think it's OK to make changes to it. But

• for code that we don't build/ship (e.g. ScheduledJob, LocalAccounts), we should avoid changing it.
• for the code that came from .NET (e.g. ComInterop), we should avoid changing it unless the original code in dotnet/runtime was also updated to use ArgumentException.ThrowIfNullOrEmpty.

Originally posted by @daxian-dbw in #19213 (comment)

Of the above, only ComInterop is documented at: src\System.Management.Automation\engine\ComInterop\README.md