@Karl, Thanks for posting in Q&A. Based on my checking, Microsoft Store for Education is being retired. Currently, we can use Microsoft Store app experience in Intune to add apps.
For Win32 app and mandatory app, based on my checking, it is not available to add in Intune for Education, You can feedback to the following link to see if we can get this in the future:
https://feedbackportal.microsoft.com/feedback/forum/ef1d6d38-fd1b-ec11-b6e7-0022481f8472
After feedback, you can monitor in the following link to see if the feature is in development:
https://learn.microsoft.com/en-us/mem/intune/fundamentals/in-development
Thanks for your understanding.
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