They have to at least mention it more than once because half of the entire human race vanished and although its likely not going to be permanent any period of time where half the population vanishes is cause enough for everyone to mention it in passing.

i think the timeline of the netflix shows haven't caught up with iw yet, the latest seasons, jj season 2, timeline was between civil war and doctor strange, so i guess we shouldn't expect any mentions yet,

Agents of Shield already mentioned that 'something weird is happening in New York' so in few episodes maybe it will have affect but yeah other mcu shows will be happening way before infinity war. Cloak & Dagger, Runaways, Luke Cage and other announced shows will be happening in 2016/2017 or early 2018 but who knows. I want so bad to agents of shield just vanish as they look at each other in shock. I loved the scenes in Infinity War and how it ended because it was finally something new and villains don't win that often in movies.

I don't think the AoS writers knew what happened in Infinity War, and it would be very strange for them to suddenly next episode do the whole "half the population vanished". The New York thing was I think them trying from what they knew to make a reference to Infinity War, but I don't think it will pan out that Episode 19 was simultaneous with Infinity War. Besides, Episode 19 is still in January 2018, but Infinity War seems to be set in Spring 2018.

The Netflix shows are currently about 10 months behind their release dates. They tend to be set roughly when they filmed. Jessica Jones: Season 2 finished in May 2017. We've got Luke Cage: Season 2 up next, coming out in June, probably set in Summer 2017. Then Daredevil: Season 3, coming out around October/November, probably set in late 2017. Then Iron Fist: Season 2, coming out around January, probably set in late 2017/early 2018. And then it's The Punisher: Season 2, coming out around Spring 2019, probably set around early 2018. That's around the time they'll be catching up to Infinity War - just as Avengers 4 is coming out. If we get any references, I don't think it will be until a while after that, because I doubt the Netflix people know what will happen in Avengers 4. But by late 2019/early 2020 Marvel Netflix releases, I would expect some references.

Here is the thing, Avengers 4 is probably picking up right after Infinity War, even though the film comes out next year. The Netflix shows may still be before Infinity War, even if they are release later. So assuming Avengers 4 corrects the “snap”, Netflix shows may never recognize Infinity War aftermath.

Maybe the fact that they mention something going down in New York in AoS and yet none of them have turned to a pile of ash yet means that the rumor about Avenger 4 being about time travel is true and they made it so Thanos never "balanced the universe" and the only reason it happened in Infinity War is because we're witnessing it from the perspective of those involved. So it would be smart of the MCU series not to include "the ashening" and the subsequent reversal and alteration of the timeline because they wouldn't remember it nor would it effect them in any way.