I personally enjoy single player more than anything else, but...
It's still online, but missing the Miiverse things, which is probably one reason a port is taking so long other than integrating everything into one screen.
So you can still find random avatars out in the wild for division support and recruit others to get medals. You can also still fight Yggralith...it just takes a bit longer to get the world enemy status complete so you can fight it.
Now that I think about it, there's still a fairly robust community playing the game.