Maybe, you don’t want management in the ATP portal, even though it’s configurable via roles, and maybe they don’t want to be there.
One thing I know is that most managers loves numbers, so why not provide them with a PowerBI report.
You can perfectly use cloud based option and there is an app for Windows Defender ATP already there for you to use.
Configure your connector and you’re all good to go
The dasboard looks like the following picture
With the many different tiles you, or your manager, can dig deeper in to events like in this following example with alert status
It’s also possible to filter data based on who a case was assigned to, who resolved the case etc.
If you have a PowerBI Pro account, you could subscribe to get scheduled reports.
You can also to quick filter
This is an easy win for your manager