Yes, it is somewhat of dark pattern IMO. It distracted me so much I added a CSS rule to my ad blocker to block it across sites. Fortunately Stack Exchange doesn't make up random CSS ids to try to defeat ad blockers so these rules covers most of the sites
stackoverflow for that site.
I saw this "hot question" because I was browsing in another browser for which I don't have the ad blocker rule setup and now here I am wasting 20-30 minutes of my life falling down the rabbit hole that is "hot network questions"
I've also added a rule to hide my points because IMO that's a dark pattern as well. I see my points go up, I get my dopamine shot, I get more addicted to the site. It's not just an addiction for points. I end up wasting time because I click the little indicator to see which questions got voted up and then often I end up clicking one of them to see what I wrote so 1-3 minutes of time lost and lots of chances for further distractions.
These rules are for uBlock Origin
There is certainly a spectrum of patterns from dark to light. Consider that Google's goal on google.com is to get you off google.com as soon as possible. The sooner they find your answer and send you send you somewhere else the happier you are.
People come to stack exchange sites generally to either ask questions or answer questions. It's arguable whether people come to browse what's hot across multiple categories (I'm sure a few do). Assuming most don't though so for those it's arguably not helping them, only a distraction. Note, you can manually browse "hot" questions on any site and for any tag so we're talking about the hot network questions, question unrelated to the site you're currently on.
This might also be a cultural norm type of issue. Where else in the world do you get 25 unrelated links shoved in your face? I'm sure people will come up with examples in the comments but at least off the top of my head it feels fairly exceptional. Walking through a store to get item A and having to pass isles of items on the way there doesn't fit since item A has a physical location so you had to pass the other items. The annoying clickbat ads by Taboola at the bottom of slashdot.org and many many other sites that are completely unrelated to the topic at hand seem like a dark pattern to me. How is this any different?
I feel like distractions in general are a dark pattern and I'm hopeful but not optimistic that there will be a "don't distract me" movement and some kind of thing like a "no unwanted distractions pledge" that companies will start following.
Maybe because I am easily distracted but it's getting to the point that all distractions to me are a dark pattern. So much of my day is responding to these distractions. Even if I manage not to follow them they still take time to clear. As one example several dating sites I'm on I need to leave notifications on since I might get a message from a prospective new friend but the app itself sends me 1 or 2 "come to the site today and search for people" notifications every day and there is no way to turn that off. So I get distracted by that 3 to 4 times day by that. In other words, 3 or 4 times a day my phone dings and I have to get it out of my pocket to check what needs my attention only to find out it's something I didn't want to be distracted by. Add up all the distractions, plus the number of times I actually follow a distraction where it leads and my life is much worse off than it would be without them.
To give another example of life in 2019, how many of you have had the experience of thinking of something you need to do on the computer/phone (check an appointment, look up something specific, add to a todo list), you look at the screen and something catches your eye, you end up following the distraction for 5 to 30 minutes. You then stop using the device only a moment later to realize you never actually did the thing you started to use the device for in the first place. This is so bad with me I've done it 3 times in a row trying to achieve the same goal and each time getting distracted into something else, spending 10-30 minutes, going away from the screen and realizing I still hadn't done the thing I set out to do.
The last 2 paragraphs are a way of trying to suggest that in 2019 "distractions" themselves are a dark pattern. For me, if look at the screen and see the points on an SE site I'd click the see where they came from. While there if I saw an interesting "hot" question I might follow. These features are not enriching my life they are taking away from it.
IMO every good site and good app should provide a way to opt-out (or better opt-in, default out) to minimize all distractions because many people are getting buried by an avalanche of distractions. In that light, that in 2019 there are too many distractions, this "hot network questions" list of 25 distractions is a dark pattern.
Note: I easily spent more than 1 hour writing and editing this answer, looking up definitions, referencing other sites, thinking and revising my answer, all because I made the mistake of using the site on a browser that didn't have "hot network quesitons" blocked. One hour of my day gone I didn not intend to spend here. If your anti-distraction skills are top notch good for you but apparently mine aren't. For those like me "hot network questions" is a dark dark pattern.