Yeah, I assumed it was part of the perks of allegiance. I was kind of surprised to see I didn't get access to the Empire Defense missions when I joined the KDF.
That said, the recent dev blog suggested that they want romulan players to have to pay dilithium to get non-Romulan ships while leveling up. Yet, the "Test of Mettle" mission allows a Romulan to get a free KDF ship... in addition to their free Romulan ships. Not sure if that is intentional or not.
I'm going to chime in here with this as a bug as I also gained access to [Test of Mettle] (which provided a free Klingon ship) and the [Tutorial] Space Chase (followed by [Manhunt])
I will say this is a bug for the free ship that I don't think Feds get and because, odd dialog of Khev suddenly shouting "Qapla'!" at the top of his lungs from a Klingon bridge aside, in Space Chase I specifically was forced to take the dialog "Too bad I am not a Romulan..."