This is (at least partially) not true. The new Manifest V3 standard requires that the Chrome browser handle all content blocking requests, instead of the extension, and the filter list must be provided to the browser by the extension. It’s true that Google wants most of the filter lists in the extension package, which requires submitting a full extension update to the Chrome Web Store. That’s a slower process than the extension just downloading a new text file every day with filter lists, which is how most ad blockers still on Manifest V2 operate.
However, extensions using Manifest V3 can still update some filters the old way, without a full update to the extension and a review process by Google. These are called “dynamic rules,” and
starting in Chrome 121 (which
arrives in January, several months before Manifest V3 becomes mandatory), up to 30,000 dynamic rules are allowed if they are simple “block,” “allow,” “allowAllRequests,” or “upgradeScheme” rules.
Maybe the filter rules required specifically for YouTube don’t work with those rule formats, I don’t know! If they’re not, then Google still allows an additional 5,000 rules with more broad capabilities. Either way, the statement “whenever an ad blocker wants to update its blocklist […] it will have to release a full update and undergo a review” is not true and can be easily disproven by
checking the Chrome developer documentation,
Mozilla’s documentation, or
a blog post that Google published a month ago.