I haven't seen anything yet on whether Brave will support it, though if I'm understanding correctly, they won't have a choice since they're using Chromium. Hopefully I'm misinformed.
Ultimately I think we must permanently return to browser ballots back by the law, like the IE bundling fallout. Otherwise friction and incentives will continue to entrench one dominant player.
Mozilla, the browser, is great.
Mozilla efforts, such as Rust, have been historically great.
Mozilla leadership is currently awful. They focus is on the wrong things - web VR and low-quality foundational AI models. Maybe because they think the web is at risk of disappearing outright. But the true enemy is Google, and they're currently its well-behaved prisoner.
Mozilla can't bite the hand that feeds it, but someone needs to point the FTC, Congress, and the EU at Google. Everything they do, buy, and work on is to point an overwhelming majority of internet users at its ad products. Chrome, Search, Android, YouTube, Apple default search engine deal, etc. Google has become inescapable. And that's rather anti-competitive if you're trying to advertise your business or selling ad tech.
Nevermind that the web commons and standards are constantly in Google's blast radius for funneling everyone into their gaping maw.
From what I understand, the arguments about self-preferencing kind of always get thrown out due to a more strict interpretation of the law. Did with Apple, and with Facebook when they were acquiring Instagram and Whatsapp.