This is generally fine!
Do you have an "opt out" to someone sending a Dislike to your post? Should that be added? Maybe, but we don't have the tooling or the norms in place to enforce this.
So if someone built an AP service that added dislike, would you feel a breach of consent if your posts were disliked and this was visible in that service?
Maybe! I'm not saying how you should feel, but I'm saying that at that point your option is to _generally revoke consent_, with some limits.
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But what is unlikely to happen is that they are unlikely to go out to every person on the fediverse and send them an informed consent letter that says "do you consent to us processing dislikes for your posts on our services?"
Why? Because it is part of the ecosystem here, even if it is not a widely used part, and they are behaving basically like a typical server in this regard!
This is where you have an implied or assumed consent and _no one thinks this is weird_.
It's an opt-out system
4/