I think all the available reactions should be different ways to indicate “I like this post.” This is because, to get to these reactions, we must first click the 
button. The tool-tip for the heart button is “Like this post.”
With this approach, I’d know that a bunch of reaction icons means that post was liked, at a glance. I wouldn’t need to study each indvidual icon.
The Fedora Logo and❓don’t fit this pattern. They don’t mean “I like this post.”
I presume 
means “I have a question about this post,” but that’s better handled by posting the actual question as a reply.
I’m borderline on the Eureka.
Maybe add rocket 
. Maybe add eyes 
— meaning watching with interest.