Tusky (an open-source mastodon client) has (or had, I hope) an integrated blacklist that prevents its users from accessing certain instances the developers find distasteful.
Mozilla could implement a similar feature to block portions of the web, or particular content, or add a feature that pro-actively fact-checked page content.
I still use a firefox fork, because it isn't chromium. But I won't be surprised if Mozilla decides to go a similar route to Tusky based on their espoused values.
