We have a set of 4 Connection servers on Windows 2012 and with Horizon 8 2206 installed. We are planning a phased migration to Windows server 2019 as follows, ONE server at a time:

1. Server will be disabled in Horizon under the servers list.
2. Horizon and ADAM software will uninstalled from one server
3. Run the vdmadmin command on another running server to remove the record of the server being uninstalled
4. Drop the 2012 server from the domain and then bring the new OS 2019 server up with the same name and IP address
5. Re-install the same version of Connection Server software as a replica and reuse the same cert with Priv key from the old server

My question is around whether mixed Windows OS versions are supported, temporarily, in addition to whether the steps above make sense. Over the course of a few days all 4 servers will be upgraded in the same way but this first one if kind of a proof of concept for the steps.