CloudAppSecurity Stale Devices

[Geoffrey_Owen]

After a device object is deleted in AzureAD, when/how will it be removed from CloudAppSecurity?

What scenario will allow a device to be displayed in CAS which no longer exists in AAD?

[#2]

If you mean historically triggered alerts and other types of data for a device then please have a look at this:
https://docs.microsoft.com/en-us/cloud-app-security/cas-compliance-trust#data-retention