I'm not a fan of your proposed changes, as they further lock down platforms.
I'd like to see better tools for users to engage with. Maybe if someone is in their Firefox anonymous (or private tab) profile they should be warned when writing about locations, jobs, politics, etc. Even there a small local LLM model would be useful, not foolproof, but an extra layet of checks. Paired with protection about stylometry :D
It seems like it would make sense to get in the habit of distort your posts a bit, and do things like make random gender swaps (e.g. s/my husband/my wife), dropping hints that indicate the wrong city (s/I met my friend at Blue Bottle coffee/I met my friend at Coffee Bean), maybe even using an LLM fire off posts indicating false interests (e.g. some total crypto bro thing).