The coming reckoning for publishers is not “because of Apple”. It’s because of the choices the publishers themselves made, years ago, to allow themselves to become dependent on user-hostile ad networks that slow down the web, waste precious device battery life, and invade our privacy. Apple has simply enabled us, the users who are fed up with this crap, to do something about it. If aggressive content blocking were enabled out of the box, by default, I could see saying the result is “because of Apple”. But it’s not. What’s about to happen is thus because of us, the users.
I'll go a step further.
The reckoning is not because the publishers chose to ally themselves with user-hostile ad networks. The reckoning is coming because before they did that, they devalued their and all their competitors' content by refusing to consider a paid model for their work on the internet.
Publishers are morose when discussing how "it would be great if people paid for content on the web, but that's not the world we live in." They forget that it was they themselves who decided that what they published was all of a sudden not worth any money from any user as soon as they opened it in a web browser.
Once they establish that their work should be free to consume on the internet, the decsion to ally themselves with the only group that thinks their content has monetary value is a no-brainer. After that decision has been made, the idea that they then wouldn't conform to the needs of their true customer is baffling.