Earlier this year, Google got the internet riled up when it tentatively planned to remove the APIs that content blocking extensions — including ad blockers — use. The proposed replacement API wouldn't be as powerful or flexible, so both users and developers forwarded their complaints to Google. However, the company is mostly sticking to its guns.
First, let's rewind a bit. The current platform used by Chrome extensions is called Manifest V2, which was introduced in 2012. Google has been working on Manifest V3 for a while now, with both new functionality and changes to existing browser features.
The change that received the most (negative) publicity was Google's intention to replace the existing webRequest API, used by every content blocking extension, with a more limited declarativeNetRequest API. Instead of extensions doing the network filtering themselves, they would provide a filter list that Chrome itself would parse. Many developers, most notably the creator of uBlock Origin and uMatrix, spoke out against the proposed changes.
Google has spent the last few months thinking it over, but for the most part, the company is sticking to its existing plan. "Chrome is deprecating the blocking capabilities of the webRequest API in Manifest V3," a developer advocate at Google wrote in a forum post, "not the entire webRequest API (though blocking will still be available to enterprise deployments)." In other words, content blockers will have to move to the new limited API at some point, or they'll stop working for regular people.
Google went on to highlight the improvements it has made to the new declarativeNetRequest API since it was first introduced. Extensions will be able to define blocking rules in two ways: during installation, and while running. The current limit is 30,000 during installation, plus 5,000 while running. Google said in the forum post, "We are planning to raise these values but we won't have updated numbers until we can run performance tests to find a good upper bound that will work across all supported devices." To give you an idea of how the limit might affect ad blockers, EasyList (the main set of rules that most ad blockers use) currently has around 76,000 rules.
These changes likely won't appease people currently using ad blockers, but the Manifest V3 standard is still months away from being implemented, and Manifest V2 likely won't be decomissioned for another year or two after that. In other words, you have plenty of time to switch to Firefox, which now blocks tracking scripts without any extensions needed.
Google has provided an official statement about the proposed changes:
"Chrome supports the use and development of ad blockers. We’re actively working with the developer community to get feedback and iterate on the design of a privacy-preserving content filtering system that limits the amount of sensitive browser data shared with third parties"
- Google Groups