Great question! I wish I could give you a satisfying binary yes or no answer, but unfortunately like most of our world, it just depends. I would say most sci-fi could be considered speculative fiction, but there might be exceptions. I found this cool chart that I think might help out. 
Safe to say most sci-fi is considered speculative though!
Source: https://annieneugebauer.com/2014/03/24/what-is-speculative-fiction/
I wish bookwyrm had a good mobile app! I forget to put my read books in there all of the time.
Speculative fiction encompasses more than just what we consider "science fiction". It is basically just a blanket term to mean stories that happen outside of our known universe. It can be futuristic, supernatural, etc. It doesn't refer to a specific genre, but can encompass multiple subgenres.
Hope that helps!
Turns out communities need to at least 3 characters. Since that is the case, I still think it makes sense to align with the subreddit name but I actually have no idea what I'm doing, just trying to help out since I want to see a speculative fiction community on here. Opening to changing the name, you seem to have much more mod/admin experience than me!
Maybe we just rip the bandaid off while it is so new and go !sf@literature.cafe. Sorry for the extra work!
Is there an easy way to do a name change on a community? sf is cooler for sure.
Not totally sure, the subreddit was called r/printsf so I just took the same name.
Great ideas thanks!
Oops! Maybe both. !printsf@literature.cafe (I think this is how you link?)
Love the instance you are creating, hope to help out as much as I can.
Considering spinning up an r/printsf clone on this instance instead of doing my actual work.
I think someone mentioned Thistlefoot on last week's thread so I picked it up this week and it's sooooooo good. Holy shit I love it.