wants to participate in the protocol exactly as intended
I don't think they want to participate in the protocol as intended at all. I think they want to gradually warp Activity Pub for their own ends.
This isn't about liking or disliking, it's about inferring future behaviour based on past patterns. That company has an abominable history. It actively impeded an international genocide trial (after it spent years facilitating the genocide).
When that's the kind of level they can stoop to I think it's madness to engage with them and expect good faith. The secret meetings haven't helped.