Comitatus and The Road Unravelled simply not dropping.
Little situation summary first.
I hadn't levelled up any of my factions before the TTK came out. Being highest levelled up furthest with Dead Orbit eventually the Kondratyuk's Escape dropped. I moved on to New Monarchy then in search of the Comitatus but no avail. The December patch dropped and within the space of 2 to 3 levels with Dead Orbit, FWC and New Monarchy, all 6 year one faction ships dropped.
But, since then, I have levelled up New Monarchy back on the search for the Comitatus. I'm nearly level 100 on my Titan and it just wouldn't drop, then I moved on to FWC where I am nearly 70 or 80 I think and nothing either. I gave up and switched to levelling up NM on my Hunter. I'm now level 40 and still no luck whatsoever.
Then I remembered something, I had unlocked the Aurora Lance (a new old PS exclusive ship you get from looting chests) just before getting the Kondratyuk's. I don't know if it is related so I am looking now for the Crypt Hammer and Outrageous Fortune to see if that is related. It probably won't be but Destiny has weird glitches so it might entirely be possible. I'll report if it does anything.
I also think this might be a possibility, if you didn't get the Year Two ships before the December patch came out and gave you the Year One ones, you just CAN'T get the Year Two ones due to some RNG related buggery. It's really annoying, I know I might just have bad RNG luck but this is ridiculous. My Warlock isn't too high levelled with factions but already higher than most who have had those ships drop being new players according to forum and help little research.
edit : I'm on XBOX ONE.
I am NM on all 3 of my characters, the highest rank of which is 90. I have yet to get this ship as a drop. I have received every last NM items multiple times over, including the new chroma gear. I have all of the emblems, shaders, armor, weapons, and ships.................except the Comitatus. This is the coolest ship in the game, in my opinion. I keep trying at it, but no joy. I think that I fell in some RNG black hole or something. LOL.