I think Maurader/Arcanist would make a fun Dark Knight job

[TouchandFeel]

I could see Maurader+Arcanist being a very viable class combo for a Dark Knight job as it would bring both some drain abilities and poison themed DOT's to the table which work well for the DRK theme as well as having a good sized HP pool from MRD which would work well for playing off of the classic Soul Eater ability where DRK could sacrifice HP to do more damage.

If DRK extended from MRD (MRD lvl.30, ACN lvl.15) then the ACN pet would not be an issue since DRK would only really pull from ACN for cross class skills and I doubt that summon would be included for them.

[Boots-365]

are they planning on bringing in a DKN

[XanderOlivieri]

are they planning on bringing in a DKN

Its one of a few classes specifically mentioned a few times in various interviews. Though its always been mentioned as a Gladiator Job.

I'd personally like to see them make a new class to fit the Dark Knight more than use an existing one.

[Nahara]

are they planning on bringing in a DKN

The short-hand for Dark Knight is and will be DRK, as it was in XI, since both XI and XIV use the same three-letter short-hand notations for jobs (as evidenced when you look at a piece of gear that's available only to certain classes).

That said, I want to reiterate what I said about this in another thread: What makes people think pairing a martial class (be it GLD or MRD) with a magic class makes for a good DRK? A Dark Knight's identity, the thing that sets it apart from other classes, has always been Souleater, the ability to consume your own HP in order to deal damage to your enemy. Sure, DRK had spells in XI, but those were mostly just filler and laughably weak given which stats DRK wanted on their gear. Leave the spell-casty knight to the Mystic Knight/Rune Fencer/whatever, because that's a much better fit than Dark Knight.

And even if you could somehow convince people that DRK really should come from ACN (or another popular example being THM), well... congratulations, you're now stuck with Ruin, Physick, Virus, and Eye for an Eye as one half of your cross-class abilities. DRK will almost assuredly be a melee DPS, and those abilities do nothing to help them do it better. DRK would benefit a hundred times more with the cross-class abilities from LNC and PGL, since those give you Invigorate, Blood for Blood, and Internal Release (and possibly even Mantra, since it's off the GCD and helps the healers bring your HP back up, since you're dealing damage to yourself).