Brave's adblocker is written in Rust [0] and compiled to native code; it's not affected by the Mv3 transition because it doesn't use extension APIs. Brave also publicly committed [1] to continuing support for Mv2 through patches.
Why make claims you have no clue about? As someone said above Brave is NOT affected, their adblocker is a the very core of the browser and a basic chromium extension.
I am also wondering if there is or will be a Chromium fork that just keeps the old code and not enforces v3 but just support both v2 and v3 and then also default to accept some alternative extension store that also has v2 extensions.
[0] https://github.com/brave/adblock-rust [1] https://twitter.com/brave/status/1574822799700541446