Now I have implemented a patch management process, but we have a server farm of 500 Windows servers not connected to the internet consisting of Windows 2000 and 2003 servers with various service ...

Microsoft announced the "general availability" commercial release of its Hotpatch capability for virtual machines, which just works with the Windows Server 2022 Datacenter Azure Edition product.

Windows Server 2012 and Windows Server 2012 R2 are no longer supported products as of Oct. 10, 2023, meaning no more patches will be arriving.