The OneDrive synchronization reports are still in preview. And it will continue for quite some time. And the following has already been rolled out:
Sync Admin Reports – Windows Support (May 2021)
Sync Admin Reports – Sort and Filter (October 2021)
Sync Admin Reports – View Aggregated Errors (January 2022).
In development are:
Sync Admin Reports – macOS support (currently plan in preview: March 2022)
Sync Admin Reports – Bulk Data Export (currently plan in preview: June 2022).
You can currently only add devices to Sync Admin reports if those devices are in the Sync OneDrive Ring Insider or Production.
In the background, however, work is also being done on improving group policies
Insider version 22.050.0306.0001: New GPO simplifies adding new clients.
Insider version 22.070.0403.0002: Old GPO has been removed.
22.050.0306.0001
OneDrive Insider version 22.050.0306.0001 was already rolled out on 3/14/2022. This included a new group policy for the OneDrive synchronization reports. However, since the documentation at Microsoft was not yet ready, I waited with the article.
To add a machine to the OneDrive synchronization reports, up to this point, the group policy had to be assigned to
Sync Admin Reports
still need to add the Tenant Association Key and then enable the group policy. This is tedious, so Microsoft has added a new Group Policy called Enable Sync health reporting to OneDrive
This group policy no longer requires a Tenant Association Key. It creates the key EnableSyncAdminReports in the registry. This is exactly described in the Microsoft documentation.
So the OneDrive version 22.050.0306.0001 contained both the old and the new group policy. Microsoft writes:
The previous group policy HKLM\SOFTWARE\Policies\Microsoft\OneDrive\SyncAdminReports is still supported and will continue to be supported for 60 days after the general availability announcement. We recommend administrators deploy the GPO now to ensure a smooth transition at this time.
22.070.0403.0002
However, OneDrive Insider version 22.070.0403.0002 took out the old „Sync Admin reports“ group policy. This created the SyncAdminReports key with the client association keys in the same place.
So if you had the old key enabled, you should enable the new key and you can delete the old key from the registry.
Comment:
A bit of a jumble that is still incomplete and riddled with errors even on the original Microsoft documentation.
Sources and links:
Hans Brender's Blog 
I can’t find the new setting EnableSyncAdminReports in the Microsoft Enpoint Manager admin center using administrative templates profiles. Any idea?
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So i have no idea, in which way Microsoft is doing with the Microsoft Endpoint Manager. So the OneDrive GPOs come with each update of OneDrive, so i do not know, how you may import the admx & adml files into the Microsoft Endpoint Manager. In case you do not find a solution, open a Ticket with Microsoft, to ask them.
The Microsoft 365 apps Admincenter -> OneDrive is still in Preview
So the old GP „Sync Admin Reports“ where you need a TAK is now replaced with „Enable Sync health reporting for OneDrive“ (withou the TAK). Both Group Policies work. The old one will still remain , I think 3 months after GA of the Microsoft 365 apps Admincenter – OneDrive
Hope thois helps
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