This makes no sense whatsoever. You could want Meta to use ActivityPub, say it's a good thing that they use an open standard, and still say you have no interest in communicating with them and stick to services where they are defederated.
You don't have an obligation to read every email you receive just because it's an open standard.
There's no logical connection between services using activitypub and you bring forced to connect to them. So I guess at least that's a point to your free speech example.