Our Operations Manager installation is an upgrade from 2007 through (currently) 2012 R2. The operating system was Server 2008 R2. I like to stay current, so I was interested in figuring out how to upgrade to Server 2012 R2. When I did a search on it, I found that there were recommendations on how to go through some complicated steps to perform the upgrade.
And then I read a few comments where people had just updated the OS. That seemed like the easier path so I did that. It worked great, after I ran all the system updates following the upgrade.