While I would think the Romulan stuff would be the main focus, there are other things that can be tested on the Fed and Klink side.
I think his point was if you're lucky enough to get a Rom invite you should test Rom stuff. The rest of us, who don't have Rom invites, can test Fed and KDF changes.
STO is about my Liberated Borg Federation Captain with his Breen 1st Officer, Jem'Hadar Tactical Officer, Liberated Borg Engineering Officer, Android Ops Officer, Photonic Science Officer, Gorn Science Officer, and Reman Medical Officer jumping into their Jem'Hadar Carrier and flying off to do missions for the new Romulan Empire. But for some players allowing a T5 Connie to be used breaks the canon in the game.