There's lots in there to take in, but here's a couple take-aways that I got out of it, at least as it relates to comics. (Comics aren't specifically called out in the presentation anywhere, but they were looking at reading habits generally, of which comics would obviously be a subset.)
First, the use of bookstore and libraries is on the decline, in favor of what they call a more "local" influence. That is, friends and family have an increasing influence over what kids read. Not by forcing things on them, but by recommendations; kids are specifically asking for certain books based on what they see/hear from other kids and grown-ups in their day-to-day lives. Obviously, this sucks for libraries and brick-n-mortar bookstores, but there is a bit of a silver lining for comic shops. Namely that if you, as a parent or older sibling or whatever, take kids with you to the comic shop when you visit every Wednesday, they're more inclined to follow your example even if you don't shove the latest issue of Archie in their hands. They'll see you buying whatever it is that you buy, and see you reading it later at home, and start to recognize the characters and take an interest.
Another thing I see is that kids are definitely being impacted by marketing. It doesn't say expressly that in the presentation, but what it says is that one of the greatest connectors between a kid wanting a book and an adult buying it for them is the recognizeability of the characters. Mom and Dad are more likely to buy a book for their kid if they're somewhat familiar with the characters. Presumably, this is shorthand for familiarity with the "safety" of the content itself -- "I saw the Avengers movie and it was acceptable for my kid, so an Avengers comic book is probably okay too and I won't have to closely examine the book for objectionable content."
And THAT is where the marketing comes in. The kids aren't necessarily seeing an ad for a Star Wars comic or whatever, but when they do express an interest in a comic, the parents' context will likely be the commercialization of that particular property. So they probably remember the Star Wars movies, but they might not have any context for Umbrella Academy, and buy the former but not the latter.
And that's part of why people get up in arms about a kid getting killed in a Batman comic. They're contextual reference for Batman is either a children's cartoon from 20-30 years ago, or a campy TV show from almost 50 years ago. So while the attitudes are changing, thanks in part to the Christopher Nolan movies, that's a slow process for people to change how they see what they recognize as the character.
Also worth noting is that there's a strong implication that kids are format agnostic. They're going to read it regardless of whether it's online or in print. My suggestion here is: why make it ANY more difficult for them to get a hold of than absolutely necessary?
But those are just my takeaways. Your own perspectives may readily grant others.