Oh yes, of course! Apologies, I really should have noted that while discussing them.
Yes. It is confirmed, via CDev response, that the Lich King’s power suppresses these instincts when the worgen is raised as a Deathknight.
Worgen Psycology: Emotion and Instinct (or lack there of)
When raised as a Deathknight, a juggernaut of the scourge, much of the individual’s identity is lost. Emotions, memories, even past addictions[1] and instincts[2] are all suppressed, overwhelmed, and replaced by Death Magic.
Which makes a lot of sense. Those worgen instincts aren’t just there for fun. Instinct serves a purpose; survival. The instinct to flee, if you’re in danger. Instinct to protect your young, keeps the next generation alive. Instinct to hunt, keeps you fed. An undead being no longer fears danger because it’s already dead, has no need to protect children if it cannot reproduce, and has no need to hunt if it never grows hungry. No need for shelter, if you never need to sleep. Whether it’s because they’re dead, or because the Lich King found them unnecessary, Worgen Deathknights have as much instinct as any dead wolf carcass.
Worgen Biology: Death
Now here, I have something to offer.
It is true that worgen get their fur, fangs, and instincts from the worgen curse, which in turn draws from the Wild God Goldrinn. If the worgen curse is drowned out by the Lich King, then why are worgen deathknights still worgen?
The answer here is simply this. A worgen’s body is, physically, worgen. When you undergo your first change, your true body turns into a worgen. Note that this is not a druid form[4]. When a worgen dies in a druid form, they return to worgen form in death[3]. When a worgen dies in worgen form, they remain in worgen form[5][6]. Either way, upon death, the worgen remains as worgen.
Therefore, a dead worgen is still, physically, worgen. A fact that surprised Jarod Shadowsong[5], as he came to realize the worgen was no mere druid form.
Worgen Deathknights: They have needs too!
So we’ve covered typical worgen instincts and behavior, and how you can just throw those out the window when it comes to worgen Deathknights. But, while we’re on the subject, there are plenty of Deathknight urges that can supplement those missing instincts.
Namely, the hunt. Worgen have that constant urge to hunt, just as Demonhunters are compelled to wreak havoc. Deathknights, in turn, have the need to cause torment. While wolves do not tend to torment their food often, the prey no doubt feels a great level of fear during the chase, and despair afterwards. This may not be the most effective means to get your torture fix, as skinning a Horde spy alive might, but it gives you a reason to hunt all the same, should you wish.
Sources
- Ask CDev Answers - Round 2 https://wow.gamepedia.com/Ask_CDev
Are blood elf death knights still afflicted by their racial addiction to magic?
No, though their new addiction, the one all Ebon Blade death knights possess, is arguably worse: the need to inflict pain. If death knights do not regularly inflict agony upon another creature, they begin to suffer wracking pains that could drive them into a mindless, blood-seeking hysteria—a far worse fate than that of those who suffer from arcane withdrawal.
- Ask CDev Answers - Round 3 https://wow.gamepedia.com/Ask_CDev
From the quest “
When the player death knights are pressed into the service of the Lich King, their minds are flooded with his indomitable will. The mind of a worgen who has not undergone the purification ritual beneath Tal’doren is in a state of constant battle between the wild, animal instincts of the curse and the rational mind of a human. With the addition of the Lich King’s control, however, the instincts of the curse are shattered by his power, leaving the logical, human mind in the service of the Scourge. And with the Lich King’s will removed, as was the case with the Knights of the Ebon Blade at Light’s Hope Chapel, only the human portions of the mind remain, giving the now free, undead worgen control over its destiny.
- https://wow.gamepedia.com/Inconspicuous_Bear
- Curse of the Worgen issue 4, pg 16. Cenarius says “This form is beyond druidism. I do not believe that what has been done can be undone.” https://cdn.discordapp.com/attachments/512036763871739925/570845199098576916/unknown.png
It was another worgen . . . minus his head. Even in death, he still retained his lupine form, something that Jarod had not expected.
Knaak, Richard A… World of Warcraft: Wolfheart (p. 341). Gallery Books. Kindle Edition.
I really should write a worgen class guide sometime in the future, to go over all this again more efficiently. But I’ll admit Deathknight lore isn’t my forte. So when my niche (worgen) overlaps with another niche (deathknights), I’ve been able to contact someone in the know about Deathknights, or even a Deathknight worgen RPer that shows their stuff. I knew this one guy a couple years ago, Deathcharge on ED, who rocked the Deathknight Worgen RP pretty well.
Anywho, here’s more thankyou bacon 
Not that you’re hungry or anything, deathknight. But still. 