Blocking ads on the Web means it’ll force publishers toward the ‘News’ app which also happens to be included in iOS 9, where it’s not possible to block ads and Apple gets a cut of money made from advertising shown via its iAd network.
Those publishers that choose not to be a part of News will be forced to build their own native apps to circumvent ad blocking, which again, will take advantage of the iAd network to monetize content.
For Apple, it’s a win-win situation where it can’t really lose. If users block ads, their iPhones will be faster and more stable and publishers will be driven toward platforms where Apple can take a cut of the cash.
What’s clear to me is that ad blocking offers serious, clear advantages to those using iPhones that could create a serious threat for publishers’ ad revenue on mobile, but it’s probably a good thing.