Since any DC can be used, I would ensure they are at the required 2016 level plus latest updates.
Regarding the prerequisites of Hybrid Cloud Trust Deployment (Preview)
Woody Chiu at RASI
221
Reputation points
https://learn.microsoft.com/en-us/windows/security/identity-protection/hello-for-business/hello-hybrid-cloud-trust (Hybrid Cloud Trust Deployment (Preview))
In the above article, one of the prerequisites is listed as "Fully patched Windows Server 2016 or later Domain Controllers".
In our on-premise, both our PDC and Secondary DC are still running server 2012 r2 though we just spun up a new DC server 2016.
To comply with the prerequisites, do we have to upgrade all DCs to server 2016, or do we only need one server 2016?
Appreciated!
Woody